Thread angle
Appearance

The thread angle of a screw is the angle between the threads.[1] This is a defining factor for the shape of a screw thread. Standard values include:
Thread standard | Thread angle | Profile | Letter code | Standards |
---|---|---|---|---|
Most V-threads (including ISO and UTS) |
60° | ![]() |
M | DIN 13 |
Whitworth threads | 55° | ![]() |
W | DIN 49301 |
Pipe thread | 55° | ![]() |
G | DIN EN ISO 228-1 |
Knuckle thread / round thread[citation needed] | 30° | ![]() |
Rd | DIN 405 / DIN 20400 |
Acme threads[2] | 29° | ![]() |
||
Trapezoidal threads[1] | 30° | ![]() |
Tr | DIN 103 |
Buttress threads[2] | 45° | ![]() |
S | DIN 2781 |
German Buttress threads[2] | 30° | ![]() |
S | DIN 513 |
Square threads[1] | 0° | ![]() |
Sq | |
Steel conduit threads | 80° | ![]() |
Pg | DIN 40430 |
References
Notes
Bibliography
- Bhandari, V B (2007), Design of Machine Elements, Tata McGraw-Hill, ISBN 9780070611412.