Buttress thread

Buttress thread form refers to one of several screw thread profiles.

"Buttress thread" in machinery

In machinery, "buttress thread" is a thread form designed to handle extremely high axial thrust in one direction. (The resistance to axial thrust in the other direction is lower, being somewhat less than that of V-threads.) The load-bearing thread face is perpendicular to the screw axis. [cite book
last = Barnwell
first = George W.
title = The new encyclopedia of machine shop practice
publisher = Wm. H. Wise & Co.
date = 1941
pages = 163
] or at a slight slant (typically 7 degrees) [US patent reference | number=5127784 | y=1992 | m=07 | d=07 | inventor=David Eslinger | title=Fatigue-resistent buttress thread] The other face is slanted at about 45 degrees. The resulting thread form has the same low friction properties as square thread but at about twice the strength. In German it is called a "saw thread" "(Sägegewinde)" because the threadform resembles saw teeth.

One application in which the average person may see buttress threads is on a tube of toothpaste with a threaded cap. The threads to hold the cap on are sometimes made in buttress form, because this form best resists the force that tends toward blowing the cap off if the tube is squeezed at inadvertent times (such as while being packed inside a traveler's suitcase).

Buttress threads have often been used in the construction of artillery, because the thread can withstand the axial load placed on it when the powder charge explodes.

"Buttress thread" in oil field tubing

In oil field tubing, "buttress thread" is a pipe thread form designed to provide a tight hydraulic seal. The thread form is similar to that of Acme thread [US patent reference | number=6893057 | y=2005 | m=05 | d=17 | inventor=M. Edward Evans | title=Threaded pipe connection] [ [http://www.glossary.oilfield.slb.com/Display.cfm?Term=buttress%20thread Oil field glossary entry for "buttress thread"] ] the force is transmitted almost parallel to the axis and thread is about the same strength as standard v threads.

ee also

* Screw thread
* Acme thread form
* Square thread form

References


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • buttress-thread — buttˈress thread noun An asymmetric screw thread with one face at right angles to and the other inclined to the shaft • • • Main Entry: ↑buttress …   Useful english dictionary

  • buttress thread — noun : a screw thread in which the driving face is made perpendicular to the axis of the screw (as in a square thread) while the back face makes an angle with the axis (as in a V thread) in order to combine efficiency in the transmission of power …   Useful english dictionary

  • Screw thread — Internal and external threads illustrated using a common nut and bolt. The screw and nut pair can be used to convert torque into linear force. As the screw (or bolt) is rotated, the screw moves along its axis through the fixed nut, or the non… …   Wikipedia

  • ISO metric screw thread — The ISO metric screw threads are the world wide most commonly used type of general purpose screw thread.[1] They were one of the first international standards agreed when the International Organization for Standardization was set up in… …   Wikipedia

  • screw thread — noun the raised helical rib going around a screw • Syn: ↑thread • Hypernyms: ↑rib • Part Holonyms: ↑screw * * * noun 1. : the projecting helical rib …   Useful english dictionary

  • bastard thread — noun : buttress thread …   Useful english dictionary

  • ratchet thread — noun : buttress thread …   Useful english dictionary

  • trapezoidal thread — noun : buttress thread …   Useful english dictionary

  • Vise (tool) — A vise or vice (see under miscellaneous spelling differences) is a mechanical screw apparatus used for holding or clamping a work piece to allow work to be performed on it with tools such as saws, planes, drills, mills, screwdrivers, sandpaper,… …   Wikipedia

  • Threaded pipe — A threaded pipe is a pipe with screw threaded ends for assembly. Tapered threads The threaded pipes used in some plumbing installations for the delivery of gases or fluids under pressure have a threaded section that is slightly conical (in… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.