Calibrating your Torque Wrench - SoFlaSportbikes.com

Scudman · 12-12-2006, 01:21 PM

Calibrating your Torque Wrench

Since a torque wrench is a valuable tool in determining bolt torque, one must wonder as to how accurate this tool really is. Well wonder no more as the directions are below. This is a general guide just to get you close, it does not replace a true calibration which is a yearly requirement in most regulated bussineses

1 Place the square drive of the torque wrench in a vise. The wrench should be parallel to ground. Use a level as a guide
2 Set the torque wrench to the torque, which corresponds to the known weight that is going to be used
3 Measure out 12? from center of torque wrench drive
4 Using suitable wire or rope suspend the known weight at the 12? mark
5 The torque wrench should register the known weight. You may gently push up or down on the wrench if it is a clicker type to feel how close you are to the ideal torque.
So, what did we just accomplish? Torque is a force defined by hanging a known weight over a known distance. So, 1 foot/lb.= one pound suspended horizontally 12? from pivot point. You probably missed this little jewel by napping in High School physics, but the Scudman explained it again.

gummo · 12-12-2006, 03:01 PM

Stickified

alecracing · 12-12-2006, 03:32 PM

So, how do I calibrate if not correct?

Scudman · 12-12-2006, 07:34 PM

Quote:

Originally Posted by alecracing

So, how do I calibrate if not correct?

Look at the torque wrench handle (clicker type). It will have a ring with set screws in it. The ring has numbers 0-9. Loosen the set screws and rotate the ring until the torque applied equals the torque reading. This adjustment is only good for 9 units, after that you may have to shim the spring or just buy a new torque wrench, they came down in price.

alecracing · 12-13-2006, 06:22 PM

Quote:

Originally Posted by Scudman

Quote:

Originally Posted by alecracing

So, how do I calibrate if not correct?

Look at the torque wrench handle (clicker type). It will have a ring with set screws in it. The ring has numbers 0-9. Loosen the set screws and rotate the ring until the torque applied equals the torque reading. This adjustment is only good for 9 units, after that you may have to shim the spring or just buy a new torque wrench, they came down in price.

SNAP-ON never comes down in price

Bubbazenetty · 12-13-2006, 06:30 PM

Mine doesn't have an adjustment knob...what do I do?

Scudman · 12-13-2006, 08:39 PM

Quote:

Originally Posted by Bubbazenetty

Mine doesn't have an adjustment knob...what do I do?

I would have to look at it, but it must have an adjuster somewhere. Maybe inside the handle,look for an allen set screw

OneBadSRAD · 12-03-2007, 03:56 AM

It's also a good idea to check it at several different settings. IE: Middle of the scale, 10-20% from the lowest setting, and 10-20% from the highest setting.

Torque wrenches are usually less accurate at their extremes. And for extreme precision you should check it at the setting you use the majority of the time.

When you're using a torque wrench make sure you use the manufacturer's suggested lubricant on the bolt threads (motor oil, moly grease, etc.) for that specific torque setting.

A more precise method of checking preload is by measuring bolt stretch, though this is usually uncommon except in the case of rod bolts.

12-12-2006, 01:21 PM	#1
Scudman Superbike Racer Join Date: Feb 2006 Location: Pembroke Pines Posts: 771	Calibrating your Torque Wrench Calibrating your Torque Wrench Since a torque wrench is a valuable tool in determining bolt torque, one must wonder as to how accurate this tool really is. Well wonder no more as the directions are below. This is a general guide just to get you close, it does not replace a true calibration which is a yearly requirement in most regulated bussineses 1 Place the square drive of the torque wrench in a vise. The wrench should be parallel to ground. Use a level as a guide 2 Set the torque wrench to the torque, which corresponds to the known weight that is going to be used 3 Measure out 12? from center of torque wrench drive 4 Using suitable wire or rope suspend the known weight at the 12? mark 5 The torque wrench should register the known weight. You may gently push up or down on the wrench if it is a clicker type to feel how close you are to the ideal torque. So, what did we just accomplish? Torque is a force defined by hanging a known weight over a known distance. So, 1 foot/lb.= one pound suspended horizontally 12? from pivot point. You probably missed this little jewel by napping in High School physics, but the Scudman explained it again. __________________ The laws of men are easily flaunted but the laws of physics are brutally self enforcing

12-12-2006, 03:01 PM	#2
gummo Administrator Join Date: Jul 2005 Location: SoFla Posts: 18,149	Stickified __________________ Florida Track Days Homestead Miami Speedway Moroso Motorsports JenningsGP www.FloridaTrackdays.com Tony at FloridaTrackdays.com

12-12-2006, 03:32 PM	#3
alecracing Senior SoFla Member Join Date: Aug 2005 Location: Ft Laud Posts: 17,601	So, how do I calibrate if not correct? __________________ There is nothing like a trail of blood to find your way back home

12-03-2007, 03:56 AM	#8
OneBadSRAD Scooter Racer Join Date: Dec 2007 Location: Pines Posts: 18	Re: Calibrating your Torque Wrench It's also a good idea to check it at several different settings. IE: Middle of the scale, 10-20% from the lowest setting, and 10-20% from the highest setting. Torque wrenches are usually less accurate at their extremes. And for extreme precision you should check it at the setting you use the majority of the time. When you're using a torque wrench make sure you use the manufacturer's suggested lubricant on the bolt threads (motor oil, moly grease, etc.) for that specific torque setting. A more precise method of checking preload is by measuring bolt stretch, though this is usually uncommon except in the case of rod bolts.

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