Thread angle

File:Thread angle.svg

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 (including ISO, NPT and UTS)	M	60°	File:Spitzgewinde.jpg	DIN 13 / ISO ? / ASME/ANSI ?
Whitworth threads	W	55°	File:Whitworth-Gewinde.jpg	DIN 49301 / BS ?
British standard pipe thread	G	55°	File:Rohrgewinde.jpg	DIN / BS / EN / ISO 228-1 / ISO 7-1
National Pipe Thread	NPT	60°	File:NPT Dimensions.svg	ASME B1.20.-1983 Pipe Threads, General Purpose, Inch
Template:Plainlist	Rd	30°	File:Rundgewinde.jpg	DIN 405 / DIN 20400
Acme thread		29°	File:Acme thread.svg	ASME/ANSI B1.5-1988Template:Sfnp
Metric trapezoidal threads	Tr	30°	File:Trapezgewinde 2.jpg	DIN 103
Buttress threads	S	45°	File:Buttress thread form.svg	DIN 2781
German buttress threads	S	30°	File:Saegengewindeprofil.jpg	DIN 513
Square threads	Sq	0° (parallel)	File:Flachgewinde.jpg	?
Panzergewinde, "steel conduit thread"	Pg	80°	File:Stahlpanzerrohrgewinde.jpg	DIN 40430
British Association (BA) thread	BA	47°Template:Nnbsp30'= 47.5°	File:British Association Thread Profile.gif	BS 93:2008
Löwenherz thread		53°Template:Nnbsp8'≈ 53.1°
Bodmer thread		50°

References

Bibliography

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• Template:MachinerysHandbook25e