How to calibrate Snap-on torque wrenches?

[wxm]

I just bought the Alltrade digital torque adapter (Amazon.com: Alltrade 940759 Powerbuilt Digital Torque Adaptor for 1/2-Inch Driver: Home Improvement). This thing is pretty cool it can be used to calibrate the torque wrenches and serves as a torque wrench itself. My cheap torque wrench was easy, there is a hex notch on the side can be used to tune the torque (well, it happens to be within the torque spec, and not need for adjustment). I also have a couple of click type SnapOn's (3/8" drive one from 5-75 ft-lb, and the other 10-100 ft-lb). But I don't see any thing there can be adjusted. Does anyone know how to calibrate a SanpOn click type torque wrench, or can it be DIY at all?

Thanks in advance.

 

[-Spike-]

Pm Tools R Us if he doesn't reply here.

 

[wxm]

Pm Tools R Us if he doesn't reply here.

Thanks. I'll do.

 

[alia176]

Let me know what you find out. I got a click Snap On wrench that I'd to calibrate some day.

 

[wxm]

Let me know what you find out. I got a click Snap On wrench that I'd to calibrate some day.

PM sent

 

[mattq]

good

calibrating these things can become a bit difficult. had my own snap on torque wrench but got a bit inaccurate because of the rough handling i was used to.

 

[wxm]

Per Spike suggestion, I did contact Tool R Us for his advise, and here is his reply that I found quite useful. As a couple of us had the similar questions, I am quoting the PM here. (Hope he doesn't mind).

Originally Posted by wxm
Hi, Kevin,

...

Basically, I have a few torque wrenches (most of them are click type Snap-on that I acquired used at ebay/craigslist), so I bought a digital torque adapter in order to check the torque reading of torque wrenches. EG, for the 5-75 ft-lb wrench, I have the target set to 35 ft-lb for both the adapter and the wrench, however, the adapter reads only 32 ft-lb while the wrench clicks at 35 ft-lb, I supposed that I need to increase the torque of the wrench but don't see anywhere that I can tune it. Am I missing something?

Thanks

Hi,

In my tool truck driving days, I had a local place calibrate torque wrenches, IIRC ~$65ea. The adjustment point is usually "tamper proof", solder, glued closed. Snap-on torque wrenches are made by CDI and Snap-on now ownes them. They have repair manuals and parts exploded views on their web site.
http://www.cditorque.com/main.html

For automotive uses, the main importance is all the fasteners on one part are tightened to the same tension. Exact torque is of lessor importance, I wouldn't worry about ~10%. In your case I would change the torque setting to compensate for where I know the wrench is out.

Thanks,
Kevin