Talk:Torque wrench/Archive 1

Unreferenced tag
I was WP:BOLD and removed the unreferenced tag from January 2007. This seems like a general article without any specific items which would require WP:CITE. If there are, please tag those areas as fact so it can be addressed. Thx. &mdash; MrDolomite &bull; Talk 14:53, 18 July 2008 (UTC)

Click Wrenches
Only certain types of click torque wrenches prevent over tightening past the desired torque; those are mostly the pneumatic gun type. Hand-ratchet click torque wrenches simply 'slip' to provide an audio and tactile signal when the desired torque is reached, they can continue pass the desired torque because after the clutch slips it strikes the inner wall of the wrench itself and stops the slipping motion. Docbrazen 07:02, 20 July 2007 (UTC)

Superscript text Small Text —Preceding unsigned comment added by Gewyonegewy (talk • contribs) 18:16, 5 September 2008 (UTC)
 * Help; I recently purchased a torque wrench (Dr. Click) I must have missed something in school. If I want to tighten (say) a sprark plug and the instructions say 18 ft/lbs. Do I multiiply by twelve (nches) to set the wrench in inch/lbs ?


 * Correct. For 18 ft-lb, set 216 in-lb.  —EncMstr (talk) 20:21, 5 September 2008 (UTC)

116.4.85.99 (talk) 03:53, 13 November 2008 (UTC) Good day! I need to use a torque wrench to test if a stud bolt on an aluminium panel can withstand 1600N of tensile force, instead of using a tensile tester. It is understood that 10N is 9.8kg. The torque wrench can only go up to 1200gm, lb, Nm, lbf and ft as units...How do I convert that into N and do I need a torque wrench with bigger units?

I would be grateful if someone could provide some information on this.

Steven, Singapore


 * 1N-m (I assume this is what you mean, anyway), according to the article, is about 1.356ft-lb, so 1600 N-m is about 1181 ft-lb, which is a hell of a lot of torque. The rear wheel axle bolt on my motorbike only needs to be tightened to 88 ft-lb, for comparison. Are you sure a torque wrench is the right tool for the job? 124.169.108.38 (talk) 07:44, 2 February 2009 (UTC)

'10N is 9.8kg' sounds incorrect to me. One kilogramme of mass, in earth's gravity at sea level, experiences a downward force (aka weight) of 9.8 Newtons. I am visualising a flat sheet of aluminium with a circular threaded rod protruding from it, and assume you wish to check that this rod may be pulled with a force of 1600 Newtons without either fracturing of pulling through or out of the panel, by turning a nut screwed onto it. The torque wrench will not directly measure linear tension on the rod; the torque required to produce a given linear tension will depend upon the pitch of the thread, the material and the size of the nut used. If all such parameters are known, a mathematician better than I would be able to calculate things for you, but maybe it would be easier to use some form of tensile tester (measure the deflection on a strong spring attached to the rod?) —Preceding unsigned comment added by 91.110.80.106 (talk) 23:37, 25 June 2010 (UTC)

Inaccuracies
I'll point out the ways that I know how to correct. There's so many leaps of uncited faith here, it's painful.

For the click type, when not in use, the force acting on the spring should be removed by setting the scale to 20% of full scale in order to maintain the spring's strength.

Depends on the manufacturer. MOST actual requiring full-zeroing out, although I know of some that require as much as a 60% preload.

Never set a micrometer style torque wrench to zero as the internal mechanism requires a small amount of tension in order to prevent tool failure due to unwarranted tip block rotation.

Where did we find this tidbit? I've never heard of that, even from my tool manufacturers themselves. Factory visits are fun.

If a micrometer tool has been stored with the setting above 20% the tool should be set to 50% of full scale and exercised at least FIVE times before being used.

I'll sum up my feelings about all this click-type stuff -- refer to your owners manual. My Armstrong, Snap-On, and Matco all require different storage methods and different calibration periods. The 3/4" drive units are the most typical, that follow what you're saying..except, in case of zeroing, it simply says to have it recalibrated. I fail to understand how running the mechanism will recalibrate it by itself, and have never heard such a thing.

In the case of the beam type, there is no strain on the component that provides the reference force except when it is in use, therefore, accuracy is inherent.

Except if you bend it, heat it, or operate it in cold..etc..etc.., which is quite easy to do. It's not perfect, sorry -- no such device really exists. The nice thing about beams is the compensation for attachment and angle-of-attack on the fastener [gives head torque, not perceived]; the problem is, it's still not a perfectly accurate device, despite the claims of the article to the contrary.

And Docbrazen was kind enough to incorrectly assume sprung torque-sticks or limiters are magical enough to stop rotating -- springs wear, it happens, and there's no calibration. Torsion springs have a limit to their twist. They produce a torque that's typically within your margin of error (10% or so, depending on application), hence their wonderful use in tightening lugnuts, but it doesn't fully cease rotating -- put 600FT/LB behind a 60FT/LB stick and see what your preloads look like. 184.153.196.39 (talk) 00:18, 3 November 2010 (UTC)

Working range
Most torque wrenches seem to have a working range measured in N-m or foot Lbs. Could someone add some information on this - eg what does N-m even stand for? Obscurasky (talk) 14:32, 10 February 2014 (UTC)


 * N-m is a newton-meter: a unit of torque equal to the force of one newton at a radius of 1 meter. Glrx (talk) 22:01, 11 February 2014 (UTC)