|
|
| Line 1: |
Line 1: |
| [[File:Square thread form.svg|thumb|200px|Dimensions of a square thread form]]
| | Greetings! I am Bev. I have usually loved residing in Maine but I will have to transfer in a 12 months or two. I am a debt collector. To do inside design is the detail I enjoy most of all. I've been doing work on my web-site for some time now. Check out it out here: http://www.primaboinca.com/view_profile.php?userid=9687516<br><br>my homepage: [http://www.primaboinca.com/view_profile.php?userid=9687516 Nike air max hyperfuse blue] |
| | |
| The '''square thread form''' is a common thread form for [[leadscrew]]s. It gets its name from the square cross-section of the thread.<ref name="bhandari203">Bhandari, p. 203.</ref>
| |
| | |
| ==Advantages & disadvantages==
| |
| The greatest advantage of square threads is that they have a much higher intrinsic efficiency than [[Acme thread form|Acme]] threads. Due to the lack of a [[thread angle]] there is no radial pressure, or [[bursting pressure]], on the nut. This also increases the nut life.<ref name="bhandari203"/>
| |
| | |
| The greatest disadvantage is the difficulty in machining such a thread. The [[tool bit|single-point cutting tools]] or [[tap and die|taps and dies]] used to cut the thread cannot have efficient rake and relief angles (because of the square form), which makes the cutting slow and difficult. Square threads also cannot carry as much load as a trapezoidal thread, because the root of the square thread is smaller. Also, there is no way to compensate for wear on the nut, so it must be replaced when worn out.<ref name="bhandari203"/>
| |
| | |
| ==Classification==
| |
| Square threads are defined as follows by [[International Organization for Standardization|ISO]] standards:
| |
| | |
| :<math>Sq\,60 \times 9</math> | |
| | |
| where ''Sq'' designates a square thread, ''60'' is the nominal diameter in millimeters, and ''9'' is the pitch in millimeters. When there is no suffix it is a single start thread. If there is a suffix then the value after the multiplication sign is the [[lead (engineering)|lead]] and the value in the parentheses is the pitch. For example:
| |
| | |
| :<math>Sq\,60 \times 18 (P9) LH</math>
| |
| | |
| would denoted two starts, as the lead divided by the pitch is two. The "LH" denotes a left hand thread.<ref name="bhandari205">Bhandari, p. 205.</ref>
| |
| | |
| {| class="wikitable" border="1"
| |
| |+ Standard pitches for metric diameters<ref name="bhandari205"/>
| |
| |-
| |
| ! Nominal diameter [mm] !! Pitch [mm]
| |
| |-
| |
| | 22, 24, 26, 28 || 5
| |
| |-
| |
| | 30, 32, 36 || 6
| |
| |-
| |
| | 40, 44 || 7
| |
| |-
| |
| | 48, 50, 52 || 8
| |
| |-
| |
| | 55, 60 || 9
| |
| |-
| |
| | 65, 70, 75, 80 || 10
| |
| |-
| |
| | 85, 90, 95, 100 || 12
| |
| |}
| |
| | |
| ==Mechanics==
| |
| {{main|Leadscrew#Mechanics|l1=Leadscrew mechanics}}
| |
| | |
| ==References==
| |
| ===Notes===
| |
| {{reflist}}
| |
| | |
| ===Bibliography===
| |
| *{{Citation | last = Bhandari | first = V B | title = Design of Machine Elements | publisher = Tata McGraw-Hill | year = 2007 | url = http://books.google.com/?id=f5Eit2FZe_cC | isbn = 978-0-07-061141-2}}.
| |
| | |
| [[Category:Screws]]
| |
| [[Category:Threading (manufacturing)]]
| |
Greetings! I am Bev. I have usually loved residing in Maine but I will have to transfer in a 12 months or two. I am a debt collector. To do inside design is the detail I enjoy most of all. I've been doing work on my web-site for some time now. Check out it out here: http://www.primaboinca.com/view_profile.php?userid=9687516
my homepage: Nike air max hyperfuse blue