Beam style torque wrench

[Anonymous Poster]

I have a Craftsman beam style torque wrench that I have used for many years (about 30 years). I know that this is not the most accurate torque wrench in the world but I was wondering if it loses accuracy over time. It still looks like it is in new condition. How do you check the accuracy of a torque wrench?

[mikim]

Some parts houses have testers -- the auto zone near me has the same ones I used to use in the A.F. to calib wrenches - call around - or --- I'm sure someone here will let you know where to send it for a real calibration. 30 years old .... you might want to be prepared to buy a new one.

[RoyJackson]

Look on the internet for calibration labs...in SW PA you should find several in the Pittsburgh area.

However, you can use a known good torque wrench to tighten a fastener to...say 50% of your beam scale. Then, you loosen the fastener with your wrench. If the indicator drops suddenly when you reach the torque value you set with another wrench (thus, breaking the fastener loose) you can have a reasonably good idea of the accuracy. Remember, torque settings are to prevent correct tightening of a fastener...and to ensure the fastener is not overtightened.
You might find an automotive repair center that has a torque tester in your area.
Even if you send it out for calibration, it shouldn't cost more then $15 just for calibration. Repair, if required, may not be cost effective.

[Bird]

</font><font color="blue" class="small">( torque settings are to prevent correct tightening of a fastener )</font>

[img]/forums/images/graemlins/confused.gif[/img] [img]/forums/images/graemlins/confused.gif[/img]?? [img]/forums/images/graemlins/laugh.gif[/img]

[normde2001]

I can't imagine a beam style wrench is accurate enough to worry about testing accuracy. plus, one never knows whether the torque the wrench "feels" is caused by torque or friction. Tighten to the middle of the range and you should be good to go.

[RoyJackson]

OOPS!!!!!!!!!!!!!

Obviously, torque wrenches are to prevent overtightening of a fasterner!

Thank you, Mr. Bird!

[uhmgawa]

</font><font color="blue" class="small">( I have a Craftsman beam style torque wrench that I have used for many years (about 30 years). I know that this is not the most accurate torque wrench in the world but I was wondering if it loses accuracy over time. It still looks like it is in new condition. How do you check the accuracy of a torque wrench? )</font>

Most which I have seen are accurate at best to +/-2%, and
+/-5% being more typical. What I have done before was put
a bolt and nut through a hole in the center of a flat bar,
and hang a known weight off the flat bar a measured distance
from the central bolt. The bolt which you 'torque' acts as
a fulcrum, the torque wrench handle is secured/held however
easiest, and you simply read the weight on the pointer
scale.

Ratchet-type torque wrenches can be calibrated similarly.

[hazmat]

<font color="blue"> I can't imagine a beam style wrench is accurate enough to worry about testing accuracy. plus, one never knows whether the torque the wrench "feels" is caused by torque or friction. Tighten to the middle of the range and you should be good to go.</font>

Yup what he said.

The beauty of beam style wrenches is that they almost never need calibration. They do, however, have a broader tolerance than other types of torque wrenches. But its still much more accurate than your "tightening by feel".

If it doesn't read "0" when not in use, simply bend the bar with your hand until it does - that's your calibration.

Certainly not worth $15 cal fee on a $30 wrench.

Happy wrenching.

[Anonymous Poster]

</font><font color="blue" class="small">( What I have done before was put a bolt and nut through a hole in the center of a flat bar, and hang a known weight off the flat bar a measured distance from the central bolt. The bolt which you 'torque' acts as a fulcrum, the torque wrench handle is secured/held however easiest, and you simply read the weight on the pointer scale.)</font>

uhmgawa... does this mean that if I hang 40 pounds, one foot from the center of the bolt it should point to 40 on the torque wrench scale?

[agcomike]

believe it or not the beam style is more accurate than the clicker style.. [img]/forums/images/graemlins/shocked.gif[/img]