Please help me calibrate my torque wrenches

[Pipe Wrench]

Hi there,

I plan on getting a Powerbuilt 940962 Drive Digital Torque Adapter, so that I can check and if necessary calibrate my two torque wrenches.

The problem is, I cannot find any documentation telling me where the adjustment provision is on either torque wrench. The cap on the end of the grip appears to not be removable. Can anybody here help me with this, please?

My better torque wrench is a Rahsol Torcofix-K (10-100Nm).
The other one is a not-so-new Craftsman (I'll look up the model and post the designation later).

If pictures of eitherl torque wrench help, I can post some.

 

[T45]

you might want to check out the exact model numbers, this also came up on google

http://www.gedoretools.com/pdf/recall_kti.pdf

 

[Pipe Wrench]

The Rahsol Torcoflex-K has the number 1087529 on it. I don't see it on the recall list.

The Craftsman Digitork has the number 960305957 on it.

 

[Pipe Wrench]

I was able to access the adjustment mechanism on the Rahsol.

The Craftsman remains a mystery.

Rahsol:

 

[T45]

If that thing is electronic, all bets are off ("digitork") .

 

[Pipe Wrench]

The Digitork is a mechanical torque wrench. I'd never buy a digital one. I think I bought it in ca 1993. Somehow it must be possible to pop the handle off. I just don't see any screw or other fastener that allows the handle to be removed. There are two small holes in the end cap, but probing them, I do not find, for example, small Allen head bolts.

 

[tvtaurus]

From experience, there is usually a plug or stocker over a hole with a small allen head screw in it. I have access to a $2000 cdi torque wrench calibration tester. I had one torque wrench purchased from a parts store that I was able to back the adjustment screw all the way off and all the way in. This made no difference in calibration, and said torque wrench was returned.

 

[guy48065]

...I was able to back the adjustment screw all the way off and all the way in. This made no difference in calibration, and said torque wrench was returned.

Some types that screw only holds the handle on & has no effect on calibration.

 

[Pipe Wrench]

On the Rahsol I found a simple pin that needed to be pushed all the way through the plastic handle. The pin holds the handle components together. I did find a broken tooth in the handle adjustment, so I will just send the Rahsol in for repair and calibration. It was too expensive (over $250, I think) to simply chuck it.

Since the Craftsman is old, and it has lioved a hard life in the trunk of three different vehicles, I am considering to replace it with a Tekton 10-150 ft-lbs/13.5-203 Nm). With the Tekton, I would also like to know how to access the calibration feature.

I have very closely looked at the Craftsman, but can't find a hidden screw in the handle area. I will post a few pictures later today when I have access to my camera.

 

[bmwpowere36m3]

How do you guarantee the Powerbuilt adapter is properly calibrated?

My recommendation: send off the torque wrench to the pros (Angle Repair, TeamTorq, etc...) and for $50-60 you'll have peace of mind that their calibrated correctly. For the DIY'er the calibration will be good for a LONG while.

 

[Pipe Wrench]

How do you guarantee the Powerbuilt adapter is properly calibrated?.

I can check the Powerbuilt Drive Torque Adaptor just the same way I can check how much my torque wrenches are off.

I just happen to be one of those people who prefer to do things themselves.

 

[Pipe Wrench]

Alright, I found the adjustment mechanism in the Craftsman. I had to remove the pivot pin from the business end of the wrench. All the components could be pulled out.

 

[bmwpowere36m3]

You implied that your using the Powerbuilt to calibrate your other wrenches... how do plan to calibrate them? Weights?

All I'll say if your time it worth something and the precision of that method is not great. I dicked around with weights before... not for me.

 

[guy48065]

You implied that your using the Powerbuilt to calibrate your other wrenches... how do plan to calibrate them? Weights?

All I'll say if your time it worth something and the precision of that method is not great. I dicked around with weights before... not for me.

Why use weights when the Powerbuilt will directly indicate the torque applied to BOTH? You carefully push on the torque wrench til it clicks, then read the captured peak on the "standard". You do have to be careful not to push past the click or the standard will catch the 2nd spike. "Real" standards catch the first peak. I've had excellent results comparing my HF digital adapter to my calibration standard--but I have a mechanical loader that doesn't overshoot the break point.

 

[guy48065]

Oh--as to the question about how to calibrate the Tekton...
On all such torque wrenches with the oxide-black hex end the end is a jamb nut that unscrews from the chrome handle. The threaded tube under it is adjustable--in to increase spring tension.

 

[bmwpowere36m3]

Why use weights when the Powerbuilt will directly indicate the torque applied to BOTH? You carefully push on the torque wrench til it clicks, then read the captured peak on the "standard". You do have to be careful not to push past the click or the standard will catch the 2nd spike. "Real" standards catch the first peak. I've had excellent results comparing my HF digital adapter to my calibration standard--but I have a mechanical loader that doesn't overshoot the break point.

So your assuming the Powerbuilt unit is calibrated and of proper accuracy/precision out the box.... I wouldn't trust it without having it verified independently first.

To check another wrench for sanity, sure. To calibrate a wrench in another matter.

 

[T45]

So your assuming the Powerbuilt unit is calibrated and of proper accuracy/precision out the box.... I wouldn't trust it without having it verified independently first.

To check another wrench for sanity, sure. To calibrate a wrench in another matter.

The OP sounds like he has access to proper test equipment, so I'd be carefull of making assumptions about what he's doing or not. In any event, let him speak for himself.

 

[royesses]

You might go to sears parts direct and look at the parts diagram of your digitork or a similar model to get a look at how it is put together. Sometimes this helps to decide how to disassemble and adjust. Just a thought. Ignore if you've already done that.
http://www.searspartsdirect.com/partsdirect/index.action

Roy

 

[bmwpowere36m3]

The OP sounds like he has access to proper test equipment, so I'd be carefull of making assumptions about what he's doing or not. In any event, let him speak for himself.

Based on which post? I feel like I'm taking crazy pills here. Unless guy48065 and Pipe Wrench are the same.

 

[Pipe Wrench]

An update, but first a comment. Someone was wondering if he was taking crazy pills. I can't answer that, but I am pretty sure I am capable of calibrating my torque wrenches sufficiently with the Powerbuilt Drive Torque Adaptor and by double-checking with the weights method.

What did I do with my torque wrenches? I did find the adjustment provisionon the Rahsol in the handle, but I found a broken tooth in the torque adjustment mechanism. Since this is an expensive torque wrench, I sent it in to the manufacturer for repair and calibration. I should get it back in a couple weeks.

I did retire the Craftsman, because it's old and because I have used it mostly for non-precision stuff like wheel bolts. I saw quite a bit of wear on the internals. I replaced this torque wrench, which I have had in my various daily drivers since the '90s, with a Tekton 24335 1/2" drive 10-150 ft-lb torque wrench. The Tekton will also live in my car. The manual of the Tekton shows the calibration screw.