Thread angle
Angle between flanks of a screw thread
From Wikipedia, the free encyclopedia
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.[1] 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°[2] |  |
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° |  [6] |
DIN 405 / DIN 20400 |
| Acme thread[7] | 29° |  |
ASME/ANSI B1.5-1988[8] | |
| Metric trapezoidal threads[1] | Tr | 30° |  |
DIN 103 |
| Buttress threads[7] | S | 45° |  |
DIN 2781 |
| German buttress threads[7] | S | 30° |  |
DIN 513 |
| Square threads[1] | 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[9] | 53° 8' ≈ 53.1° | |||
| Bodmer thread[10] | 50° | |||
| Thury thread[11][12] | 47° 30' = 47.5° |
