The thread angle of a screw is the angle between the threads. 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, NPT and UTS) |
60° | M | DIN 13 / ISO ? / ASME/ANSI ? | |
| Whitworth threads | 55° | W | DIN 49301 / BS ? | |
| Pipe thread British standard pipe thread |
55° | G | DIN / BS / EN / ISO 228-1 / ISO 7-1 | |
| Knuckle thread / round thread | 30° | Rd | DIN 405 / DIN 20400 | |
| Acme thread | 29° | ? | ASME/ANSI B1.5-1988 | |
| Metric trapezoidal threads | 30° | Tr | DIN 103 | |
| Buttress threads | 45° | S | DIN 2781 | |
| German Buttress threads | 30° | S | DIN 513 | |
| Square threads | 0° | Sq | ? | |
| Steel conduit thread aka Panzergewinde |
80° | Pg | DIN 40430 | |
| Löwenherz thread | 53° 8' | ? | ? | ? |
| Bodmer thread | 50° | ? | ? | ? |
Famous quotes containing the words thread and/or angle:
“One sought not absolute truth. One sought only a spool on which to wind the thread of history without breaking it.”
—Henry Brooks Adams (1838–1918)
“I fly in dreams, I know it is my privilege, I do not recall a single situation in dreams when I was unable to fly. To execute every sort of curve and angle with a light impulse, a flying mathematics—that is so distinct a happiness that it has permanently suffused my basic sense of happiness.”
—Friedrich Nietzsche (1844–1900)