View source for Thread angle

{{short description|Angle between flanks of a screw thread}}
[[File:thread angle.svg|thumb|right|300px|Diagram of a thread angle]]

In [[mechanical engineering]], the '''thread angle''' of a [[screw]] is the included angle between the [[Threading (manufacturing)|thread]] flanks, measured in a plane containing the thread axis.<ref name="Bhandari2007p203">{{Harvnb|Bhandari|2007|p=203}}.</ref> This is a defining factor for the shape of a [[screw thread]]. Standard values include:
{{clear}}

{| class="wikitable" border="1"
! Name
! Code
! Angle
! Profile
! Standards
|-
| Most V-threads (including [[ISO metric screw thread|ISO]], [[National pipe thread|NPT]] and [[Unified Thread Standard|UTS]])
| M
| 60°
| [[File:Spitzgewinde.jpg|120px]]
| [[Deutsches Institut für Normung|DIN]] 13 / [[International Organization for Standardization|ISO]] ? /  [[American Society of Mechanical Engineers|ASME]]/[[American National Standards Institute|ANSI]] ?
|-
| [[British Standard Whitworth|Whitworth threads]]
| W
| 55°
| [[File:Whitworth-Gewinde.jpg|120px]]
| DIN 49301 / [[British Standards|BS]] ?
|-
| [[British standard pipe thread]]
| G
| 55°
| [[File:Rohrgewinde.jpg|120px]]
| DIN / BS / [[European Committee for Standardization|EN]] / ISO 228-1 / ISO 7-1
|-
| National Pipe Thread
| NPT
| 60°
| [[File:NPT_Dimensions.svg|120px]]
| ASME B1.20.-1983 Pipe Threads, General Purpose, Inch
|-
| {{plainlist|
* [[Knuckle thread]]<ref>[http://www.gewinde-normen.de/en/knuckle-thread-din-405.html Knuckle Thread DIN 405]</ref><ref>[http://www.gewinde-normen.de/en/knuckle-thread-din-20400.html Knuckle Thread DIN 20400]</ref><ref>[http://www.bornemann-gewindetechnik.de/en/products/threading-technology/knuckle-threads.html Bornemann]</ref>
* Round thread
}}
| Rd
| 30°
| [[File:Rundgewinde.jpg|120px]]<ref>[http://www.bornemann-gewindetechnik.de/dateien/pdf/en/Rundgewinde_2_ZG.PDF Knuckle thread]</ref>
| DIN 405 / DIN 20400
|-
| [[Trapezoidal thread forms#Acme thread characteristics|Acme thread]]<ref name="Bhandari2007p204">{{Harvnb|Bhandari|2007|p=204}}.</ref>
|
| 29°
| [[File:Acme thread.svg|120px]]
| ASME/ANSI B1.5-1988{{sfnp|Machinery's Handbook|1996|pp=1716}}
|-
| [[Trapezoidal thread forms#Trapezoidal metric thread characteristics|Metric trapezoidal threads]]<ref name="Bhandari2007p203"/>
| Tr
| 30°
| [[File:Trapezgewinde 2.jpg|120px]]
| DIN 103
|-
| [[Buttress thread]]s<ref name="Bhandari2007p204"/>
| S
| 45°
| [[File:Buttress thread form.svg|120px]]
| DIN 2781
|-
| German [[buttress thread]]s<ref name="Bhandari2007p204"/>
| S
| 30°
| [[File:Saegengewindeprofil.jpg|120px]]
| DIN 513
|-
| [[Square thread]]s<ref name="Bhandari2007p203"/>
| Sq
| 0° (parallel)
| [[File:Flachgewinde.jpg|120px]]
| ?
|-
| [[Panzergewinde]], "steel conduit thread"
| Pg
| 80°
| [[File:Stahlpanzerrohrgewinde.jpg|120px]]
| DIN 40430
|-
| [[British Association screw threads|British Association (BA) thread]]
| BA
| 47°{{nnbsp}}30'{{nbsp}}= {{#expr: 47 + 30/60}}°
| [[File:British Association Thread Profile.gif|90px]]
| BS 93:2008
|-
| [[Löwenherz thread]]<ref>[http://www.gewinde-normen.de/en/loewenherz-thread.html Löwenherz thread]</ref>
|
| 53°{{nnbsp}}8'{{nbsp}}≈ {{#expr: 53 + 8/60 round 1}}°
|
|
|-
| [[Bodmer thread]]<ref>[http://www.gewinde-normen.de/en/bodmer-thread.html Bodmer thread]</ref>
|
| 50°
|
|

|}

==References==
===Notes===
{{reflist}}

===Bibliography===
*{{Citation | last = Bhandari | first = V B | title = Design of Machine Elements | publisher = Tata McGraw-Hill | year = 2007 | url = https://books.google.com/books?id=f5Eit2FZe_cC | isbn = 978-0-07-061141-2}}.
* {{MachinerysHandbook25e}}

[[Category:Screws]]
[[Category:Metalworking terminology]]
[[Category:Threading (manufacturing)]]