Thread angle

Diagram of a thread angle

In mechanical engineering, the thread angle of a screw is the included angle between the thread flanks, measured in a plane containing the thread axis. This is a defining factor for the shape of a screw thread. Standard values include:

Name Code Angle Profile Standards
Most V-threads M 60° including DIN 13 / ISO, NPT and UTS
Whitworth threads W 55° DIN 49301 / BS
British standard pipe thread G 55° DIN / BS / EN / ISO 228-1 / ISO 7-1
National Pipe Thread NPT 60° ASME B1.20.-1983 Pipe Threads, General Purpose, Inch
 Rd 30° DIN 405 / DIN 20400
Acme thread 29° ASME/ANSI B1.5-1988
Metric trapezoidal threads Tr 30° DIN 103
Buttress threads S 45° DIN 2781
German buttress threads S 30° DIN 513
Square threads Sq 0° (parallel) ?
Panzergewinde, "steel conduit thread" Pg 80° DIN 40430
British Association (BA) thread BA 47° 30' = 47.5° BS 93:2008
Löwenherz thread 53° 8' ≈ 53.1°
Bodmer thread 50°
Thury thread 47° 30' = 47.5°

References

Notes

  1. 1 2 3 Bhandari 2007, p. 203.
  2. ↑ BS 84: 1956
  3. ↑ Knuckle Thread DIN 405
  4. ↑ Knuckle Thread DIN 20400
  5. ↑ Bornemann
  6. ↑ Knuckle thread
  7. 1 2 3 Bhandari 2007, p. 204.
  8. ↑ Machinery's Handbook (1996), pp. 1716.
  9. ↑ Löwenherz thread
  10. ↑ Bodmer thread
  11. ↑ Brooks, Randall C. "Standard Screw Threads for Scientific Instruments. Part 1: Production Techniques and the Filière Suisse." History and Technology, vol 5, 1988, pp. 68.
  12. ↑ Thury thread

Bibliography