Reading Assignment
- 29.1 Introduction to Thread Manufacturing
- 29.2 Thread Making
- 29.3 Internal Thread Cutting-Tapping
- 29.4 Thread Milling
- 29.5 Thread Grinding
- 29.6 Thread Rolling
- (10.3 – Allowance and Tolerance)
Recommended
- Study Guide – Threads and Threading
- Video: How to Cut a Fine Thread on a Lathe
- Three Wire Method of Measuring Pitch Diameter (video)
- From Fox Valley Technical College:
Outline
Functions of Threads
- Fastening
- Adjustment
- Power Transmission
Thread Terminology
- Depth
- Pitch
- Major Diameter
- Pitch Diameter
- Minor Diameter
- Side
- Root
- Crest
- Thread Angle
Importance of Pitch Diameter
Measuring pitch diameter
Thread Specifications
1. Basic Major diameter (fraction or decimal) followed by a hyphen.
2. Number of threads per inch
Relationship to pitch
Sharp V
Others
4. Series of the thread, followed by a hyphen
Graded Pitch Series
Constant Pitch Series
5. Class of fit (1, 2, or 3)
6. Designation as external (A) or internal (B)
7. Indication of left-hand (LH)
8. Indication of multiple thread (Double or triple)
9. Thread length if not full
10. Finish, etc.
Metric Threads
2 Groups of Threads
- General Purpose
- Fine
Metric Thread Note
- M20 X 1.5 5g6g
- M Metric Form
- Basic Major Diameter
- Pitch
- Tolerance (Grade and Position)
- See Chapter 10.3 – Allowance and Tolerance
Thread Manufacturing
Tap Drilling
Size of hole in relation to Major Diameter
Types of Taps
- Taper, Plug, Bottoming
- Forming Taps
Tap Sizes (Tolerance Designation H/L)
Dies
Other Thread Manufacturing Methods
- Cutting Threads on a Lathe
- Chasing Threads
- Rolling Threads
- Milling Threads
- Grinding Threads
Additional Resources
