Contents
SECTION 1 — GENERAL DRAFTING STANDARDS
SECTION 2 – Unigraphics Practices
SECTION 4 — PREFERRED LIMITS AND FITS FOR CYLINDRICAL PARTS
4.5 RECOMMENDED TOLERANCE SYSTEM
SECTION 5 — DRAWING NUMBERS AND REVISIONS
SECTION 6 — GENERAL DIMENSIONING AND TOLERANCING
6.3 GENERAL DIMENSIONING RULES
6.5 APPLICATIONS OF DIMENSIONS
7.3 DEFINITIONS AND TECHNICAL ISSUES
SECTION 8 — WELDS AND WELD SYMBOLIZATION
SECTION 9 — SCREWS, NUTS AND WASHERS
SECTION 10 — FACILITIES DESIGN STANDARD
10.4 DRAWING SCALE PROVISIONS/NOMENCLATURE
10.8 MANUAL DRAWN DETAILS, SECTIONS, ELEVATIONS, FLOOR PLANS, ETC.
10.15 REVISIONS AND MODIFICATIONS
10.16 FACILITY DOCUMENT NUMBER
10.18 SECTION AND DETAILING NOMENCLATURE
10.20 ELECTRONIC DRAWING REVIEW
10.21 FINAL SUBMITTAL OF DRAWINGS
SECTION 11 — DETAILED CHECKING PROCEDURE
11.2. Checking practice will be as follows:
SECTION 1 — GENERAL DRAFTING STANDARDS
1.1 SCOPE
This section defines general rules and practices to be followed by all
designers and drafters to produce design drawings of consistent and
professional quality. The contents of this section are intended to be
consistent with various American national standards listed in Table
1.1. Because of the broad scope of the design and drafting activities and
the need for an accurate interpretation of the drawings produced, any use of
special or local practices is strongly discouraged.
The accuracy and adequacy of the design and drafting work and its compliance
with the applicable standards remain the responsibility of the designer or
drafter. Nothing contained in this manual shall be construed as relieving the
designer or drafter of the individual responsibility for producing quality
drawings.
1.2 GENERAL RULES
1.2.1 All drawings shall comply with rules and guidelines for
dimensioning and tolerancing given in Section 6.
1.2.2 Commercially available components are to be used whenever
possible. Catalog number, short description, supplier name, and quantities are
to be given on the parts list.
1.2.3 Each detail shall be drawn on a separate sheet except for
tooling, weldments, and architectural drawings.
1.2.4 Each detail is to contain all information needed for
fabrication independent of other drawings. This includes, but is not limited
to:
(a) Specific materials called for by name,
identifying number, and specification.
(b) Material hardness and hardness depth.
(c) Annealing or stress relieving.
(d) Surface finish symbols.
(e) Weld symbols with joint sizes and other
requirements (See Section 8).
(f) Testing specifications, such as pressure
tests, vacuum tests, dye penetrant tests, magna-flux tests, radiographic tests,
etc.
(g) Finish specifications such as painting,
plating, etc.
(h) Brazing specifications.
(i) Calculated weight for heavy components. In
special cases add provisions for lifting.
(j) Identification of all assemblies with the
drawing number.
1.2.5 Sub-assemblies, in general, are to be drawn in the same
orientation as their assembly.
1.2.6 Dimensions given are to be the ones used to fabricate, inspect,
and match other parts.
1.2.7 Prints are not to be turned in with penciled or penned
markings. Drawings are to be revised to reflect such markings. See Section S on
Drawings Numbers and Revisions.
1.2.8 All drawings are to be brought up to date and revisions noted
in the revision block (see Section 7).
1.2.9 Reasonable simplified drafting practices shall be used.
Repetition, excessive use of hidden lines, unnecessary views, shading, and
overuse of section lines are to be avoided.
1.2.10 The term “TYP” shall not be used. The number of
specific places must be noted. The “X” is a full character height or
upper case. (Example: 2X).
1.2.11 The use of multiple sheet drawings should be avoided if
possible. If multiple sheet drawings must be used they must all have the same
log number and document number listed in title blocks. All sheets must have the
same title listed in title blocks. All sheets must be of the same size and
scale. When revising multiple sheet drawings, the revision levels (i.e., the
last two (2) digits of the log number and document number) must be updated on
all sheets.
1.2.12 All dimension, text, notes will be in capital letters, block
form, and aligned horizontally with the drawing title block. The exception is
for art work, labels, and logos that are specified on a drawing.
1.2.13 All dimensions shall be decimal values. The use of fractions
is to be avoided. The exception is in the identifier for thread sizes, both
fraction and decimal values are acceptable.
1.2.14 No symbols are to be used unless otherwise approved or
specified in national standards.
1.2.15 All characters height will be .13. All sectionals, views, and
identifiers text will be .25 in height and may be in BOLD characters.
1.2.16 All title block titles will reflect the W. B. S. titles
description on the first four (4) or less of the title block.
1.3 VIEWS PRESENTATION
1.3.1 All drawings shall be produced using the “third angle
orthographic projection” system. The third angle system is preferred as
the American standard because the views are the same as those obtained by
observing the object from the front, top, side, or rear as indicated by
directional arrows in Figure
1.1. The arrangement of typical views is shown in Figure
1.2. A minimum number of views, necessary to completely describe the
object, shall be used.
1.3.2 Sectional views shall be placed as close as practical behind
the arrows, showing the shape and construction of the object at the cutting
plane (see Figure
1.3).
If it becomes necessary to rotate a sectional view, the degree of rotation
and direction are specified.
A sectional view must be identified by its title consisting of the full word
SECTION followed by the pair of letters; for example, SECTION A-A, SECTION
B-B, etc. Avoid use of letters I, O, Q, S, X, Y and Z for sectional views.
Lettering shall be upper case.
1.3.3 Detail views shall be shown in the same plane and in the same
arrangement as in the principal view. Two ways of identifying the area of
detail are shown in Figure
1.4. The view scale is specified directly below the view (and its title).
1.4 SECTION LINING
For general use a cross-section lining symbology depicting cast iron (see Figure
1.3) shall be used on detail and assembly drawings, regardless of actual
material. When two or more materials must be identified individually in a
drawing, use the material-specific symbology of the latest ANSI Standards
wherever applicable.
1.5 PRINT FOLDING FORMAT
For ease of handling and filing, prints shall comply with the folding format
depicted in Figure
1.5. Final folded will be approximately 8.5 inch vertical x 11.0 inch
horizontal.
1.6 CHECK DRAWINGS
1.6.1 In general, drawings will be reviewed for general compliance
with the following:
a. Established standards
b. Manufacturing feasibility
c. Dimensional tolerance considerations
d. General Safety practice
e. Simplicity
f. Economy
g. View alignment
h. Scale
i. Materials
j. Fit of mating parts
SECTION 2 – Unigraphics PRACTICES
SECTION 3 – AutoCAD PRACTICES
3.1 SCOPE
The purpose of this section is to outline general AutoCAD practices that
have been implemented to promote drafting efficiency, and access and
portability of the design drawings.
3.2 AutoCAD PRACTICES
3.2.1 All drawings produced on the AutoCAD system shall comply with
the applicable ANSI standards and the standards not included in this manual.
3.2.2 Access to the AutoCAD system will be unless specifically exempted by the
Supervisor, or the responsible engineer.
3.2.3 A new drawing shall be initiated by downloading a standard
formatted blank drawing (via AutoEDMS) containing APS-designated title block
and border. An appropriate size FORMAT scaled to fit the drawing’s requirements
shall be used. Do not explode the FORMAT.
3.2.4 Use of multiple sheets in a single electronic file should be
avoided. See Section 1.2.11.
3.2.5 Drawings shall be created with all features in full size, drawn
at 1:1 scale.
3.2.6 The drawing coordinates x,y = 0,0 shall be on lower left corner
of the screen.
3.2.7 Associative dimensioning shall be used. The only exception will
be when the parts must show break lines.
3.2.8 All text shall be in ROMANS vertical font, (not slanted).
Character height will be .13 or multiples of dependent on drawing scale.
3.2.9 All dimensioning symbols will be of standard shapes and sizes.
An electronic file of the symbols will be provided by the D&D Supervisor.
Refer to latest ANSI Standards in Dimensioning and Tolerancing Book, Appendix
C, Figure C-1.
3.2.10 Hatch patterns available in the standard version of AutoCAD
shall be used. (C.I. is preferred when nothing else applies).
3.2.11 Colors and line types shall be assigned by layers in all new
drawings. The layers shall be identified by names, rather than by numbers as in
the existing drawings. This will ensure the layers’ uniformity in the new
drawings without causing conflict when old drawings are imported. The layers
shall be identified as follows:
|
LAYER |
COLOR NO. |
COLOR |
LINETYPE |
|
BORDER |
9 |
Light Blue |
Continuous |
|
CENTER |
1 |
Red |
Center |
|
DIM |
4 |
Cyan |
Continuous |
|
HATCH |
8 |
Light Grey |
Solid |
|
HIDDEN |
3 |
Green |
Hidden |
|
OUTLINE |
7 |
White |
Continuous |
|
PHANTOM |
5 |
Blue |
Phantom |
|
TEXT |
2 |
Yellow |
Continuous |
|
TB_INFO |
2 |
Yellow |
Continuous |
|
TB_TEXT |
4 |
Cyan |
Continuous |
|
TITLEINF |
Light Yellow |
Continuous |
|
|
MISC |
6 |
Magenta |
Continuous |
3.2.12 Color number 0 (zero) shall be reserved for transporting files
and inserting blocks.
3.2.13 The line width for each layer shall remain fixed. Refer to
latest ANSI Standards for more information. (see Figure 3.3).
3.2.14 When saving the electronic file, the GRID and UCS Icon shall
be off, unnecessary views and sections shall be eliminated, and any other
extraneous information shall be purged.
3.2.15 Dimension styles and its variables have built-in default
values. These values should not be changed or modified except for the length
scale factor, which may be modified for auxiliary views and section views,
depending on their scale.
SECTION 4 — PREFERRED LIMITS AND FITS FOR CYLINDRICAL
PARTS
4.1 SCOPE
This section covers preferred limits and fits for cylindrical parts used in
the design of APS mechanical components. The tables included in this section
are based on ANSI B4.1-1979 (R1987). For purchased parts such as shafts,
dowels, bearings, bushings, etc., fits and allowances outlined in this section
shall be used when manufacturers’ recommendations are not available.
4.2 DEFINITIONS
|
Allowance: |
Allowance is the intentional difference between the |
|
Tolerance: |
A tolerance is the total by which a specific dimension may |
|
Basic Size: |
The basic size is that diameter to which allowances and |
|
Fit: |
Fit is the general term used to signify the range of |
|
Clearance Fit: |
A clearance fit is one having limits of size so |
|
Interference Fit: |
An interference fit is one having limits of size so |
|
Transition Fit: |
A transition fit is one having limits of size so |
|
Basic Hole System: |
A basic hole system is a system of fits in which the |
|
Basic Shaft System: |
A basic shaft system is a system of fits in which the |
4.3 SELECTION OF FITS
In selecting limits of size for any application, the type of fit is
determined first, based on the use or service required from the equipment being
designed. Then the limits of size of the mating parts are established to insure
that the desired fit will be produced. The standard fits shown herein should
cover most applications.
4.4.1
RC Running or Sliding Fits: (Table
4.1)
RC 1. Close Sliding Fits
are intended for the accurate location of parts which must assemble without
perceptible play.
RC 2. Sliding Fits are intended for
accurate location but with greater maximum clearance than class RC 1. Parts
made to this fit move and turn easily but are not intended to run freely and in
the larger sizes may seize with small temperature changes.
RC 3. Precision Running Fits are about the
closest fits which can be expected to run freely. They are intended for
precision work at slow speeds and light journal pressures, but are not suitable
where appreciable temperature differences are likely to be encountered.
RC 4. Close Running Fits are intended
chiefly for running fits on accurate machinery with moderate surface speeds and
journal pressures where accurate locations and minimum play is desired.
RC 5. Medium Running Fits are intended for
higher running speeds or heavy journal pressures or both.
RC 6. Medium Running Fits are intended for
applications where more play than RCS is required.
RC 7. Free Running Fits are intended for
use where accuracy is not essential or where large temperature variations are
likely to be encountered or under both these conditions.
RC 8. Loose Running Fits are intended for
use where materials such as cold-rolled shafting and tubing, made to commercial
tolerance are involved.
4.4.2 LC Locational Clearnace Fits (Table
4.2)
LC 1 through LC 11 Transition Fits are intended for parts which are
normally stationary but which can be freely assembled or disassembled. They run
form snug fits for parts requiring accuracy of location, through the medium
clearance fits for parts such as spigots, to the looser fastener fits where
freedom of assembly is of prime importance.
4.4.3 LT Locational Transition Fits (Table
4.3)
LT 1 through LT 7 Transition Fits are a compromise between clearance
and interference fits, for application where accuracy of location is important
but either a small amount of clearance or interference is permissible.
4.4.4 LT Locational Interference Fits (Table
4.4)
LN 2 and LN 3 Locational Interference Fits are used where accuracy
of location is of prime importance, and for parts requiring rigidity and
alignment with no special requirements for bore pressure. Such fits are not
intended for parts designed to transmit frictional loads from one part to
another by virtue of the tightness of fit, as these conditions are covered by
force fits.
4.4.5 FN Force and Shrink Fits (Table
4.5)
FN 1 Light Drive Fits requires light assembly pressures and produce
more or less permanent assemblies. They are suitable for thin sections or very
long fits or in cast-iron external members.
FN 2 Medium Drive Fits are suitable for ordinary steel parts or for
shrink fits on light sections. They are about the tightest fits that can be
used with high-grade, cast-iron external members.
FN 3 Heavy Drive Fits are suitable for heavier steel parts or for
shrink fits in medium sections.
FN 4 Force Fits are suitable for parts which can be highly stressed
or for shrink fits where the heavy pressing forces required are impractical.
4.5 RECOMMENDED TOLERANCE SYSTEM
The unilateral system of tolerance is recommended, in which the tolerance on
each part (shaft and hole) is disposed in only one direction from the design
size, plus for the hole and minus for the shaft. See
Example
For an example, examine the fits and allowances of a 1″ OD x 1/2″
ID “home-made” sleeve bearing* carrying a rotating 1/2″ OD shaft
(see Fig. 4.0). It has been determined that the bearing will be pressed into a
steel plate with a medium drive fit (FN 2), and the shaft will be given a free
running fit (RC 7).
Plate/Bearing Fit from Table
4.5:
|
1″ Nom. Size, Hole = |
+ 0.8 thousandths |
+ .0008 |
|
|
– 0.0 thousandths |
Plate = 1.0000 dia. |
– .0000 |
|
|
Shaft (Bearing OD) = |
+ 1.9 thousandths |
+.0000 |
|
|
+ 1.4 thousandths |
Prg OD = 1.0019 dia. |
-.0005 |
Bearing/Shaft Fit from Table
4.1:
|
1/2″ Nom. Size, Hole = |
+ 1.6 thousandths |
+ .0016 |
|
|
– 0.0 thousandths |
Prg ID + .5000 dia. |
– .0000 |
|
|
Shaft = |
– 2.0 thousandths |
+ .000 |
|
|
– 3.0 thousandths |
Shaft OD = .4980 dia. |
– .001 |
_________________________
*Purchased sleeve bearings generally come with OD oversize by the amount
necessary to achieve the proper press fit in a normal reamed hole. It is
therefore necessary for the designer to specify the hole size and tolerance to
accommodate the bearing accordingto the “Limits of Clearance” in the
tables, or to use the manufacturer’s recommendations if available.
SECTION 5 — DRAWING NUMBERS AND REVISIONS
5.1 SCOPE
This section describes various drawing numbers and their use on the student
drawings. The drawing numbers are assigned and controlled by the system
specified by the instructor.
5.2 DRAWING NUMBERS
The following drawings numbers are presently in use:
5.2.1 Number
A log number is a seven (7) digit number preceded by a letter (letter A
at present), that is assigned to the drawing by the DCC upon written request.
This number is assigned sequentially to the drawings as well as other APS
documents. The log numbers often appear to be at random on related drawings
when the requests for numbers are not submitted at the same time. Once a log
number is assigned to a drawing, it never changes except for its revision level
designation, (i.e., its last two (2) digits). (The last two (2) digits are for
revision designation and should coincide with the revision level of the
document number).
Because of its small field length (8), the log number is easier to use in
database and DOS applications. It is, therefore, commonly used for storing,
searching and retrieving a specific drawing from a large database of drawings
and documents. In APS drawings, the log number is always used in conjunction
with a drawing number (either a Logical Drawing Number or a Prototype Drawing
Number, see below) in the title block.
5.2.2 Document Number
In September 1992 the DCC replaced the existing septum with a logical
drawing numbering system that allowed users to identify relationships between
assemblies, sub-assemblies, and their parts. A Document Number consists of
three (3) parts: (1) a WBS number, (2) a six-digit sequence, called Logical
Drawing Number (LDN), and (3) a two-digit sequence identifying the drawing
revision number.
The multiple-digit WBS number, explained in “Document Control Center, Hands-on Guide for APS Users,” identifies a major component assembly of
the APS Project. The six-digit LDN is composed of three (3) two-digit sequences
(see Figure
5.1), representing (from left to right) a sub-assembly, a sub-sub-assembly,
and a part. Figure 5.1 illustrates how this hierarchical breakdown is used for
a photon shutter assembly.
The division of a major component assembly (defined by the WBS number)
into sub-assemblies, sub-sub-assemblies, and parts is the responsibility of the
cognizant engineer and his designer. For a specific drawing they propose to the
DCC a complete document number consisting of the WBS, LDN, and revision number.
The DCC’s responsibility is limited to verifying that the proposed number has
not already been assigned.
In order to avoid any conflict with the old design numbers not based on
LDN, the number zero is not allowed in the first digit (left most) of the LDN.
This ensures that the assigned number will always be different from the old
numbers which contained only five (5) digits.
5.2.3 Prototype Drawing Number
A prototype drawing number has the same structure as document number
except that the former is preceded by the letter “P” indicating a
prototype. This drawing number is used when the components being designed are still
in a prototype phase and may not be used in the APS machine. When a prototype
drawing is considered to be acceptable, the prototype drawing number is
converted to the logical drawing number by dropping the letter “P”
and incrementing the revision number.
5.2.4 Sketch Number
A sketch number is a five-digit number preceded by the letter
“S”. Drawings with sketch numbers are generally used by engineers and
physicists to convey design information to the design and drafting staff. Their
use is restricted to R&D activities. Although the sketch numbers are issued
by the DD, it does not store or in any way control drawings with sketch
numbers.
The use of sketch numbers on the APS production drawings is not to be
used. Asof January 1996 sketch numbers will no longer be used.
5.2.5 Electronic File Number
The Experimental Facilities Division (XFD) uses electronic file numbers
in its Design Exchange System, which is being set-up to exchange design
drawings of standard components between XFD, beamline users, and other outside
organizations. An electronic file number consists of a descriptive identifier
of field length two (2) followed by the logical numbering sequence (LDN)
explained above in sub-section 5.2.2. The descriptive identifier essentially
replaces the long WBS number. Its first field is a letter which represents a
component group, and the second field is a number assigned sequentially to
different components of that group.
As an example, an existing APS Drawing Number 1415972-810000-00,
consisting of WBS 1.4.1.5.9.7.2, LDN 810000, and revision 00, is identified as
V2810000 in the Design Exchange System.
5.3 DRAWING REVISIONS
5.3.1 Revision – The term “revision” refers to any
change on the drawing after the drawing has been approved and submitted to the
instructor.
5.3.2 Revision Number – The last two digits of the logical
drawing number and the prototype drawing number identify the revision number.
The original release is identified by -00, and subsequent releases are numbered
sequentially from -01 to 99.
5.3.3 Document Change Note – A Document Change Note (DCN)
must be submitted to the DCC with the revised drawings for approval and to
update the database.
5.3.4 Revision Symbol – A revision symbol is an identifying
number, enclosed in an equilateral triangle as shown in Figure
5.2. Revision symbols shall be used to locate the revision in the field of
the drawing. To avoid crowding of revision symbols, a single revision symbol
may be used to identify the changes if they are properly identified and
described in the (DCN).
5.3.5 Location – Revision symbols shall be located as near
as possible to the notes, lines, views, or dimensions which are changed so as
to minimize the number of symbols.
5.3.6 Multiple Changes – All changes to a drawing
incorporated at one time shall be identified by the same revision number. The
changes shall be identified by a revision tri-marker with that corresponding
revision number.
5.3.7 Revising a Change – Whenever a change is revised, a
new symbol shall be placed next to the previous one.
5.3.8 Revision Block – Each revision shall be recorded in
the revision block of the drawing (see Figure
5.2) showing (1) revision symbol, (2) the DCN number, (3) initials of the
person making the change, (4) signed initials of the person authorizing the
change, and (5) date of the revision.
SECTION 6 — GENERAL DIMENSIONING AND
TOLERANCING
6.1 SCOPE
Rules and guidelines for dimensioning and tolerancing are intended to
establish uniform practices for specifying and interpreting design
requirements. As a rule, all APS drawings shall comply with ANSI Y14.5M-94,
“Dimensioning and Tolerancing,” in its entirety. If there is a
conflict, the rules given in this section shall take precedence.
Excerpts of ANSI Y14.5M-82 are included in this design manual as Appendix
6-A. For a quick reference, only the most commonly used dimensioning and
tolerancing requirements are outlined below.
6.2 DEFINITIONS
6.2.1 Dimension. A dimension is a numerical value expressed
in appropriate units of measure and indicated on a drawing along with lines,
symbols, and notes to define a geometric characteristic of an object.
6.2.2 Reference Dimension (REF). A reference dimension is a
dimension without tolerance used only for information purposes and does not
govern production or inspection operations. The preferred method is to place
the reference dimension within parentheses.
6.2.3 Nominal Size (NOM). The nominal size is the
designation which is used for the purpose of general identification, that is,
1.500 IPS, .062 stock size, etc.
6.2.4 Basic Dimension. A numerical value used to describe
the theoretically exact size, profile, orientation, or location of a feature or
datum target. It is the basis from which permissible variations are established
by tolerances on other dimensions, in notes, or in feature control frames.
Basic dimensions are shown on the drawing in enclosed rectangle.
6.2.5 Maximum Material Condition (MMC). The condition in
which a feature of size contains the maximum amount of material within the
stated limits of size; for example, minimum hole diameter, maximum shaft
diameter.
6.2.6 Allowance. An allowance is the intentional difference
between the maximum material limits of mating parts. It is the minimum
clearance or maximum interference intended between such parts.
6.2.7 Tolerance. The total amount by which a specific
dimension is permitted to vary. The tolerance is the difference between the
maximum and minimum limits.
6.2.8 Standard Tolerances. Dimensions shown without
tolerances are controlled by the standard tolerances shown in the title block,
except dimensions in welding symbols; those labeled STOCK, NOM, REF, MAX, MIN,
BASIC; and similar dimensions that are otherwise controlled.
6.2.9 Datum. A datum is the origin from which the location
or geometric characteristics of features of a part are established. NOT
A CENTERLINE.
6.2.10 Feature. The general term applied to a physical
portion of a part, such as a surface, hole, or slot.
6.3 GENERAL DIMENSIONING RULES
6.3.1 Dimensioning of parts must convey enough information to define
clearly the engineering intent, so that no scaling of drawings is required, nor
any assumptions need to be made. Functional dimensional values is the preferred
method.
6.3.2 Each dimension must be expressed clearly so that it will be
interpreted only one way. No factional dimensions are to be used only decimal
dimension is the accepted practice.
6.3.3 No surface, line, or point may be located by more than one
toleranced dimension in any one direction. If a dimension is repeated, it is
marked REF.
6.3.4 Dimensions shall be selected and arranged to avoid accumulation
of tolerances.
6.3.5 Dimensions are shown on the view that most clearly represents
the form of the feature being dimensioned.
6.3.6 Dimensions are shown outside the outline of the part unless
clarity is impaired.
6.3.7 Dimensioning to hidden lines shall be avoided.
6.3.8 Dimensions must be selected to give the required information
directly so that no calculations are needed to arrive at usable figures.
6.3.9 Where practicable, the finished part should be defined without
specifying the manufacturing method. Thus, only the diameter of a hole is given
without specifying how it is to be produced.
6.3.10 Dimensions out of scale shall be avoided.
6.3.11 Unidirectional dimensioning is to be used, that is, all
dimensions and notes should be aligned with the bottom of the drawing.
6.4 UNITS OF MEASUREMENT
6.4.1 All drawings produced by students shall use the inch as the
unit of measurement as per ANSI Y14.5.
6.5 APPLICATIONS OF DIMENSIONS
Dimensions are applied with dimension lines or as notes with leaders.
Dimension lines indicate linear distance between feature centers or surfaces
directly or by the use of extension lines (see Figure
6.1).
6.6 TOLERANCING
Dimensional tolerances may be expressed as follows:
6.6.1 Title Block Tolerancing – The tolerances are specified
in the title block and depend on the number of decimal places used in the basic
dimension (Figure
6.2).
6.6.2 Limit Tolerancing – The high (maximum) value of a
dimension is placed above the low (minimum) value as shown in Figure
6.3.
6.6.3 Plus and Minus Tolerancing – The basic dimension is
followed by plus and minus tolerance values (Figure
6.4).
6.6.4 Geometric Tolerancing – The tolerances are defined by
means of a Feature Control Frame (Figure
6.5) which specifies dimensional limits for an individual geometric feature
such as location, orientation, form, profile and runout. The Feature Control
Frame is divided into several compartments containing (1) geometric
characteristic symbol (which is, when applicable, preceded by a diameter
symbol), and (3) datum references as needed.
Symbols used for geometric tolerances are shown in Figure
6.6. These symbols can be down-loaded from a CAD file available from the
design room supervisor.
Figure
6.7 shows typical uses of geometric tolerances on a drawing.
6.7 GENERAL TOLERANCING RULES
6.7.1 Tolerances shall be assigned, directly or as default values, to
all dimensions in a drawing.
6.7.2 Title block default tolerances shall be used whenever feasible
or modified for the drawing requirements.
6.7.3 For stock such as bars, sheets, tubings, and structural shapes,
tolerances established by industry or Government standards shall apply unless geometric
tolerances are specified explicitly.
6.7.4 Tolerances shall be specified to meet actual design
requirements. Do not use restrictive tolerances simply because they can be
easily generated on a CAD station.
6.7.5 Bilateral tolerances should be selected instead of unilateral
tolerances when plus and minus tolerancing is used. Preference should be given
to equal plus and minus values.
6.7.6 Tolerances shall have the same number of decimal places as the
base dimensions, and have the same character height as the dimensions.
SECTION 7 — SURFACE FINISH
7.1 INTRODUCTION AND SCOPE
This section outlines the method for specifying the geometric characteristics
of surface irregularities on drawings. Surface roughness, waviness and lay are
the only surface irregularities to be considered unless otherwise stated in
drawings. These symbols and numerical value classifications shall be used to
define the roughness, waviness and lay of a surface in drawings.
7.2 APPLICABLE DOCUMENTS
|
MIL-STD-100 |
Engineering Practice |
|
ANSI B46.1 |
Surface Texture, Surface Roughness, Waviness and Lay |
|
ANSI Y14.36 |
Surface Texture Symbols |
|
ISO 468 |
Surface Roughness-Parameters, Their Values and General |
ANSI B46.1 and ANSI Y14.36 must be stated on all drawings when surface irregularities
need to be controlled.
7.3 DEFINITIONS AND TECHNICAL ISSUES
All terms related to the surfaces of solid material shall be defined per
ANSI B46.1 and ANSI Y14.36. These terms are summarized in Figures 7.1,
7.2,
7.3,
and 7.4.
Some commonly used terms are outlined as follows:
Surface – The surface of an object is the boundary
which seperates that object from another object. Substance or space and
produced by such means as abrading, casting, coating, cutting, etching, plastic
deformation, sintering, wear, erosion, etc.
Roughness – Roughness is the surface feature of
random and repetitively spaced minute or smaller from the center line.
Roughness height is the measured profile height deviation taken within sampling
length. The average spacing between adjacent peaks is known as the roughness width
spacing.
Waviness – Waviness is a more global surface feature
than roughness. It is the mean surface upon which roughness can be
superimposed. Waviness height is the peak-to-valley height of the modified
profile from which roughness and flaws have been removed. The average spacing
between adjacent peaks of such a surface is known as the waviness width
spacing.
Thus, waviness refers to the larger mean surface upon which roughness is
superimposed. However, the roughness number defined deviation from mean centerline.
Lay – Lay defines the direction of the predominant
surface pattern. This surface pattern or tool mark is determined by the
production method used. This feature may be necessary in sealing of joints and
sliding applications of mating surfaces.
It is important to note that these numerical values have dimensions. In APS,
the dimensions shall be micro-inches for roughness height and inches for
waviness height, waviness width and roughness width unless otherwise stated.
Most standard and common machining operations are good for roughness height
about 63 micro-inches. A summary of the roughness height of other machining
practices are included in one of the attached.
So do not specify surface finish control in metric format whenever it
can be done. Finally, better surface finish is very costly. So
care must be taken not to request better surface finish than required.
In communicating with metric dimensions, these dimensions and their meaning
are going to be quite different.
SECTION 8 — WELDS AND WELD SYMBOLIZATION
8.1 SCOPE
Preferred design and drafting practices for welds and welding symbolization
are given in this section. As a policy, weldments shown on the drawings shall
conform to the established procedures recommended by the American Welding
Society, and the weld symbols shall comply with the ANSI/AWS A2.4,
“Symbols for Welding and Non-destructive Testing”.
8.2 DEFINITIONS
8.2.1 Welding – Welding is a process in which metals are
joined by inducing melting at the abutting surfaces. Welding may be performed
with our without the use of a filler metal.
8.2.2 Welding Processes – Welding processes may be
classified into the following main categories:
|
Induction Welding (IW): |
|
|
Arc Welding (AW): |
Submerged arc, inert gas metal arc, atomic hydrogen, |
|
Gas Welding (GW): |
Air acetylene, oxy-acetylene, oxy-hydrogen, gas pressure, |
|
Thermit Welding (TW): |
Pressure and non-pressure, (not recommended for vacuum |
|
Resistance Welding (RW): |
Spot, seam, projection, flash, upset, percussion. |
|
Electron Beam Welding (EBW): |
|
|
Laser Welding (LW): |
|
|
Pulse-arc Welding (PAW): |
|
|
Diffusion Welding (DFW): |
8.2.3 Weld Symbols – Weld symbols are ideographs used to
represent the type of weld specified. Figure
8.1 shows the most commonly used weld symbols and examples of their use.
Refer to ANSI/ASW A2.4 for a complete list of weld symbols.
8.2.4 Supplementary Weld Symbols – Supplementary weld
symbols, shown in Figure
8.2, are used to provide additional information about the extent of the
weld, where and how welding is performed, and the contour of the weld bead.
8.2.5 Welding Symbols – Welding symbols are graphical
symbols made up of up to eight elements that convey explicit welding
instructions. The eight elements, shown in Figure
8.3 are: reference line, arrow, basic weld symbols, dimensions and other
data, supplementary weld symbols, finish symbols, tail and specification, and
process or other reference.
SECTION 9 — SCREWS, NUTS AND WASHERS
9.1 SCOPE
This section specifies a preferred list of screw type fasteners and washers
to be used on APS components. It covers only a limited set of screws, nuts,
plain and lock washers that meet most of our general requirements. It in no way
shall restrict the use of other materials or types where design problems deem
them necessary.
9.2 DIMENSIONS
The dimensions of the various fastener elements are given in the respective
American national Standards Institute standards cited in Table
9.1. Plain washer dimensions are tabulated in Table
9.2. The “TAD DATA” Screw Data Slide Calculator shall serve as
the dimensional reference for the standard screws and lock washers. This slide
gives data on screw sizes #0 – 1 in. diameter which probably represents 95% of
our requirements. For other sizes, refer to the respective standards.
9.3 MATERIALS
The materials covered by this standard are limited to steel, stainless steel
and brass. These are identified by the respective ASTM standards or as noted in
Table
9.1. Material call out shall follow examples shown in Table 9.1.
9.4 SCREW SIZES
Although this standard does not restrict choice of sizes, Tables
9.3 and 9.4
list the sizes that are commercially available. However, preference should be
given to sizes listed in the Argonne Stores Catalog. It is recommended that the
UNC series be specified for machine screws because coarse threads make up the
bulk of production. The notable exception is size #10-32 where a full selection
of lengths is available. Recommended tap drill sizes are given in Table
9.5.
9.5 THREADS
Threads are to be manufactured in accordance with the coarse, fine or
8-thread series, class 2A or class 3A, of ANS B1.1, “Unified Screw
Threads”. Socket screws shall, however, be manufactured to the UNR Thread
Series (ANS B1.7) with controlled root radius.
9.6 DRAWING REPRESENTATIONS
Screws, bolts, nuts and threads shall be represented in drawings as shown in
Tables 9.1,
9.2,
9.3,
9.4,
and 9.5.
9.7 SUSPECT/COUNTERFEIT PARTS
The U.S. Department of Energy and the Argonne National Laboratory are
concerned that Suspect/Counterfeit parts and materials are not incorporated
into APS systems and components. A list of Suspect/Counterfeit parts will be
provided to the successful bidder of goods and services. The awarded seller of
items and services to the APS will assure that none of the indicated
Suspect/Counterfeit parts and materials are incorporated or installed on or
within components or equipment. These special requirements will be noted within
drawings, specifications, statements of work, and general instructions.
Typical Notification Statement on APS Drawings
NOTE:
This drawing/application requires the use of high-strength fasteners such as
grade 5 or grade 8 bolts. In an effort to prevent the introduction of
Suspect/Counterfeit parts into components, a list denoting unfavorable fastener
manufactures will be provided by your instructor. The Suspect/Counterfeit
fasteners, (as noted by their headmarkings), are not to be used in the
construction or installation of items identified within this drawing.
SECTION 10 — FACILITIES DESIGN STANDARD
10.1 SCOPE
The following standards defines in general the measures to be taken by
A/E-Firms and Design Build Firms doing work for Project. This will assure
compatibility between the above mentioned firms and the Engineers, Designers
and Drafters, and will provide drawings and designs of professional quality at
minimum cost to the Project.
Consistent with the objective of this standard is the need to discuss with
and achieve with the above mentioned firms agreement as to the particular
drafting methods employed.
Because of the broad scope of design and drafting activities and the need
for universally uniform interpretation of such work, avoid local and special
drafting practices. Standards and practices are intended to be compatible with
those of industry and governmental agencies, therefore the following general
drafting standards are presented.
Floor plans are to be oriented with north arrow pointing either up or to the
right – never down or to the left.
10.3 DRAWING SCALES
All floor plans for construction drawings will be drawn at a scale of
1/4″ per ft. If this is not feasible, downsizing is permitted to 1/8″
of 1/16″ upon approval of the Project Manager.
Increasing size of the floor plans is permissible by a factor of 1/8″
per ft. (Example, 3/8″, 1/2″).
Group details and sections as much as possible to maintain uniform scale on
individual sheets. Do no combine details of one scale with a floor plann of a
different scale on the same sheet.
Building elevations, interior elevations and building cross sections shall
be drawn at a minimum of 1/4″ per ft. (Preferred).
Increasing or decreasing size of building elevations, interior elevations,
and building cross sections is acceptable at a rate scale of 1/8″ per ft.
(Example, 3/8″, 1/2″, 1/4″, 1/8″).
Details and sections shall be drawn in scale utilizing either 1/2″ =
1′-0″, 1″ = 1′-0″, 1 1/2″ = 1′-0″, 3″
=1′-0″. If details or sections are not drawn in scale, deviation will be
noted., i.e., scale: N.T.S.
10.4 DRAWING SCALE PROVISIONS/NOMENCLATURE
All electronic drawing files will be drawn to limits, i.e., scale; no
electronic files will be accepted when drawings are plotted at a different
scale than what is shown on the drawing. All drawings will have conventional
architectural and engineering scales: Example:
|
Architectural |
All Engineering |
|
1/16″ = |
1″ = 10′ |
|
3/16″ = |
1″ = 20′ |
|
3/8″ = |
1″ = 30′ |
|
1/8″ = |
1″ = 40′ |
|
1/4″ = |
1″ = 50′ |
|
3/8″ = |
1″ = 60′ |
|
1/2″ = |
1″ = 100′ |
|
3/4″ = |
1″ = 200′ |
|
1″ = |
1″ = 300′ |
|
1-1/2″ = |
1″ = 400′ |
|
3″ = |
1″ = 500′ |
|
6″ = |
1″ = 600′ |
All deviations must be approved prior to usage by your instructor.
10.5 DRAWING REDUCTION
If drawings are reduced from their original size for publication, etc., the
following note must appear on the drawing: ” Warning – This Drawing
Has Been Reduced.”
10.6 DIMENSIONING
All dimensions shown on drawings will be true dimensions to the graphic
representation shown, if not, dimensions will be accompanied by the following:
Example:
|
4′-0″ |
|
______________________ |
|
N.T.S. |
|
or |
|
4′-0″ |
|
______________________ |
10.7 PLOTTING
A plotting schedule will be provided on each drawing defining screen
colors and pen weights used to create the drawing. See Figure
10.1 for further information.
10.8 MANUAL DRAWN DETAILS, SECTIONS,
ELEVATIONS, FLOOR PLANS, ETC.
Manual drawn details, sections, elevations, etc. shall be avoided.
All drawings shall include both a standard scale and a graphic scale.
10.9 DRAWING SHEETS
Final original drawings shall be presented on plain bond paper (standard
printer paper).
Standard sheet sizes shall be as shown below. Select size to maximize
drawing efficiency. All drawing sets/packages shall be of one size only.
Standard Sheet Sizes (Inches)
|
Letter |
|
|
|
Designation |
Width |
Length |
|
A |
8-1/2 |
11 |
|
B |
11 |
17 |
|
C |
17 |
22 |
|
D |
22 |
34 (Preferred) |
|
E |
34 |
44 |
|
F |
28 |
40 |
10.10 TEXT
Standard text fonts will be used. These are as provided in AutoCad and
Unigraphics. Deviations in font styles will be submitted for approval prior to
usage. See Figure
10.2 for further information.
All notes, headings, legend, etc., will be placed on default layers as
prescribed in AutoCad/Unigraphics. Deviations will be accepted if placed on a
layer called “text” any further deviations will be submitted for
approval prior to usage.
Insofar as all drawings are drawn to scale, i.e., limits, text must also be
drawn to the appropriate scale. See Example #5 for further information.
10.11 CADD COMPATIBILITY
All students shall provide their instructor with electronic drawing data
compatible with the lab CAD Systems. The following is a list of CADD computer
programs being used at this time:
AutoCad – Version 2004 or earlier
Unigraphics NX5 or earlier
10.12 SYMBOLS
Symbols shall be as per the standard systems in the latest versions of
AutoCad and Unigraphics. Should non-standard symbols be required, prior written
approval shall be obtained from the instructor.
10.13 LAYERING
Layering shall be as per the standard layering system in the latest versions
of AutoCad, and Unigraphics. Should non-standard layers be required, prior
written approval shall be obtained by the APS Project Manager or CADD System
Manager. (See Figure
10.3).
10.14 ABBREVIATIONS
Abbreviations shall be used only when their meanings are unquestionably
clear and shall be per ANSY Y1.1, “Abbreviations for Use on Drawings and
in Text,” of the American Society of Mechanical Engineers.
When abbreviations are used, the words and/or terms and their abbreviations
shall be defined in a legend.
10.15 REVISIONS AND MODIFICATIONS
Revisions and modifications to CADD files must be done electronically, no
hand changes will be accepted, this includes reversional changes in the title
block.
10.16 FACILITY DOCUMENT NUMBER
10.16.1 General description of identification system.
A technical document shall be identified by the assignment of an
alphanumeric designation consisting of a Project Identifier, Document Status
Identifier, and Document Identifier (sheet number) as follows:
|
XXXXX-XXX |
X |
XXXX |
|
Project |
Status |
Document |
The project identifier is assigned by the Document Control Center upon request of the ANL Project Manager.
The document status identifier shall denote the project phase in which the
document was originated and shall have one of the following alpha codes:
- “P” – Pre-Conceptual or Feasibility
- “S” – Conceptual Design
- “D” – Preliminary Design – Title I
- “W” – Final Design – Title II
- “T” – Tenant Layout
- “G” – General
The document identifier shall identify the type of document and the
corresponding assigned number. This shall be an alpha code to denote the
document type, i.e., drawing or non-drawing.
A drawing-type document shall be denoted by the particular discipline
associated with the drawing as follows:
- “A” – Architectural
- “C” – Civil
- “E” – Electrical
- “F” – Fire Protection
- “G” – General
- “I” – Interiors
- “L” – Landscaping
- “M” – Mechanical
- “S” – Structural
- “T” – Non-Drawing Document
Each drawing document shall be numbered sequentially within its associated
discipline.
For the purpose of clarity, wherever practical the same numerical number(s)
should be assigned to the floor plans in all disciplines. For example, if 2 is
assigned to a floor plan in architectural discipline, then 2 should be assigned
to the same floor plan in mechanical and electrical disciplines.
- Drawing Documents
J0046-101-D-A001
J0046-101-D-E001
- Non-Drawing Documents
J0046-101-D-T001
J0046-101-W-T001
(See Figure
10.4)
10.17 CADD FILE NAME
A CADD file shall be identified by a 12-character name. It shall consist of
an 8-character file name, a period, and a 3-character file extension.
10.17.1 Elements of a Cadd File Name
a. Characters 1 thru 3 shall reflect the building number or utility.
Example:
XXX XXXXX . XXX
|
Building No. |
Sequential No. |
Dwg. (Default) |
|
Facility No. |
00001 |
|
|
00002 |
|
400 – Experiment Hall
410 – Control Center
500 – Site Utilities
(See Figure
10.4)
10.17.2 Additional Information
a. The following information shall also be provided along with the
electronic files.*
- Listing of all WBLOCKS and BLOCKS incorporated.
- Customized LISP routines.
- Drawings List.
- Linetypes, symbols, etc.
a. Electronic file name and
drawing
“J” – number and title.
b. Manual drawing title and “J” –
number*
- Listing of all text fonts and styles used other than the
stock font files offered in AutoCad or ASG.
b. The 5-digit code shall be a unique number sequentially assigned
throughout the project and each sheet will be uniquely numbered.
c. File Extension.
The 3-character file extension shall always be DWG for AutoCAD files.
d. Examples:
40000001.DWG
40000002.DWG
40000010.DWG
40100001.DWG
40100102.DWG
10.18 SECTION AND DETAILING
NOMENCLATURE
The letters for sections will be in sequential order beginning with the
letter A through Z. If more letters are required, a double-lettering system
will be employed, such as AA, BB, etc.
The numbers for details will be in sequential order beginning with the
number one and so on. (See Figure
10.5).
10.19 TITLE BLOCK
A title block for each project shall be provided to the A/E and D/B firms
for their use in either an AutoCad DWG or DXF format. A sample is enclosed.
(See Figure
10.1).
10.20 ELECTRONIC DRAWING REVIEW
Electronic drawing files will be submitted for review at various stages of
the project; typically interim files shall be submitted at approximately 2 week
periods for review by the CADD Manager to insure adherence to the general
drafting standards as specified.
The electronic files will be reviewed for the standards listed and the
following generally accepted CADD practices.
- Unnecessary fragmented lines.
- Improper layering as described.
- Improper text size and fonts.
- Scale.
- Dimensioning Scale.
- Unnecessary electronic files.
a. Pieces or blocks outside the
electronic border.
- Multiple blocks, lines, text inserted on top of each
other, etc.
10.21 FINAL SUBMITTAL OF DRAWINGS
Drawings shall be presented on plain bond paper. No grayscale or colors are
permitted on detail views. Grayscale and color are permitted for rendered
pictorial views.
SECTION 11 — DETAILED CHECKING PROCEDURE
11.1 SCOPE
This section defines general rules and practices to be followed to check
drawings for consistency and professional quality.
11.2. Checking practice will be as
follows:
a. Final checked drawings must be signed by all persons designated in the
title block.
b. Detailing Checklist:
- Inspect the drawing to see
that the projections and sections are made in such a way as to show most
clearly the form of the piece and the work to be done on it. Make sure
that any workman looking at the drawing will understand what the shape of
the piece is and how it is to be molded or machined. Make sure that the
delineation is correct in every particular, and that the information
conveyed by the drawing as to the form of the piece is complete. - Check all dimensions to see
that they are correct. - Scale all dimensions and see
that the drawing is to scale and that dimensions are associated
dimensions. - See that the dimensions on the
drawing agree with the dimensions on the layout. - Wherever any dimensions is out
of scale, see that the dimension is so marked. ( XX ). X.XXX this
practice is not recommended. - Investigate any case where the
dimension, the scale of the drawing, and the scale of the layout do not
agree. - See that all figures are
correctly formed and that they will print clearly, so that the Shop can
easily read them correctly. - See that the overall dimensions
are given. - See that all dimension
extension lines go to the correct part of the drawing. - See that all arrow points go
to the correct dimension extension lines. - See that proper allowance is
made for all fits. - See that the tolerances are
correctly given where necessary. Ask if you don’t know the tolerances to
be applied. - See that all dimensions given
agree with the corresponding dimensions of adjacent parts. - Be sure that the dimensions
given on a drawing are those that the machinist will use and that the
worker will not be obliged to calculate in order to obtain the necessary
measurements for machining or checking his work. - Avoid strings of dimensions
where errors and tolerance can accumulate. It is generally better to give
a number of dimensions from the same reference surface or center line. - When holes are to be located
by boring on a horizontal spindle boring machine or other similar machines
give dimensions to the centers of bored holes in rectangular coordinates
and from the center lines of the first hole to be bored, so that the
operator will not be obliged to add measurements or transfer gages. - Give all weld sizes, show
proper weld symbols, and insure accessibility for all welds. - Show weldment cuttings only
when necessary. - Provide “breather”
holes on closed weldments. - Study the sequences of
operations in machining, and see that all finish marks are indicated. Try
to make the part in your mind with the information shown on the drawing. - See that the finish marks are
placed on the lines to which dimensions are given. - See that methods of machining
are indicated where necessary. - Insure adequate stock for
machining. - Give all drill, ream, and tap
sizes. - Insure proper use of geometric
tolerancing symbols. - Avoid special taps, drills,
reamers, etc. unless such tools are specially authorized. - Where parts are right- and
left-handed, be sure that the hand is correctly designated. No drawing
should contain both parts. - When possible, make parts
symmetrical, as to avoid making them right- and left-handed, but do not
sacrifice correct design or satisfactory operation to accomplish this. - When heat treatment is
required, the heat treatment should be specified. Ask, if uncertain, of
the proper heat treat process. - Verify the title, the scale,
the drawing number, and series on both the drawing and the drawing record
sheet. - Note required finishing
operations, i.e., amoloy, electroless nickel, black oxide, etc. - Utilize 1/16, 1/8, 1/4, 1/2,
and full-scale only, for details. Consult with the standard design
supervisor for exceptions. - Consider the kind of material
required for the part and the various possibilities of casting, forging,
welding, or otherwise forming the part from this material. Then consider
the machining operations to see whether changes in form or design will
reduce the number of operations or the cost of machining. - See that parts are detailed
with reference to the economical use of material, and whenever possible,
utilize standard sizes of stock and material readily obtainable. In the case
of alloy steel, special bronze, and similar materials, be sure that the
material can be obtained in the size required. - Insure that the Bill of
Material on assembly drawings properly calls out the type of material,
stock size, quantity required, vendor part number, and source. - When preparing assembly
drawings, see that the part can readily be assembled with the adjacent
parts. - Make sure that in being
assembled, the piece will not interfere with other pieces already in place
and that the assembly can be taken apart without difficulty. - When specifying purchased
components, insure complete information for ordering, including correct
catalog numbers. - When using purchased
components, insure proper interfacing with fabricated parts, i.e., tapped
holes, bearing fits, shaft diameters, mounting feet, etc. - Utilize standard hardware
whenever possible. - When detailing a new casting,
assign a new pattern number. - Insure proper application of
standard drawing note stamps. - Obtain from the design
engineer, and note on the assembly drawing, any applicable information
regarding motor speeds, traverse rates, pulley ratios, specification
number, technical information, etc.
(Adapted from the Argonne National Laboratory APS Design and Drafting Standards)
