Craftsman Microtork Torque Wrench project

[b.well]

I was picking up some tools from my local ebay tool guy yesterday and when he wouldn't sell me a torque wrench for sale with some watchers he offered me one missing a part(s) for free. Looked in good condition and was Craftsman USA so I accepted it.

Do I have any chance to restore this?

I know it's missing at least two parts(and will need calibration):

1. Oring (I have this)
2. Handle bottom (can't find this)

Anyone have one of these, or parts, or know what I need to find?

I do not know what torque it is at right now. I'll try to get a better gauge of that today and relieve some pressure if it's high.

Thanks much!

 

[Dumber than lumber]

Real calibration will cost more than for a half-way decent torque wrench.
Maybe you can do some Steam-punk thing with it?

 

[b.well]

Thanks. I know the harbor freight ones are only $20 but I will hold onto restoring this for awhile longer.

 

[Ralf11]

you can check the torque with a fixture clamped in a vise, some wts. and a ruler

 

[b.well]

Thanks Ralf11. I don't have a weight set but I have plenty of heavy stuff around that I can weigh and use

 

[vjquan]

I have this torque wrench and use it regularly. I would use one of those digital torque adapters that you can get at HF to calibrate it.

 

[b.well]

vjquan thanks for posting. Am I just missing the one part at the bottom of the handle? Does it pop on/off? Guessing they are never suppose to come off. Calibration is just part of the project. The harder task is finding the missing part.

 

[b.well]

I don't know how far in the adjustment hex bolt sets inside of the handle. If I rotate the handle until the hex bolt just sits inside the lip of the handle the wrench reads 70 ftlbs. It's likely the hex bolt sits farther inside and the wrench is set to it's minimum as is recommended for storage. If I rotate the handle until the wrench reads 20ftlbs (it's minimum) the end of the hex bolt is 1/2" inside the handle. It's at least good to know it isn't set at it's max ftlbs!

 

[vjquan]

The bottom of the handle is a press fit cover. The distance from the stud to end of nut is right at about 5 mm, so that should get you in the ballpark.

 

[b.well]

Thank you for the picture. Very helpful. So you think i am not missing any critical part and i only need to adjust the screws properly?

The bottom of the handle is a press fit cover. The distance from the stud to end of nut is right at about 5 mm, so that should get you in the ballpark.

Sent from my SM-G960U using The Garage Journal mobile app

 

[vjquan]

Correct. I also measured the end of the hex bolt to handle and it measures in at 5/8". It remains constant throughout its range as the internals rotate with the handle.

The handle is locked to the shaft with the two nuts. As you rotate the handle, the hex threaded rod rotates and compresses a spring which gives it its torque setting. The fact that your shaft is changing in the handle means you're rotating the nut and not the shaft.

 

[b.well]

That means i just need to tighten the rear bolt and all should move as one. I hope a deep socket is enough. There is at least an inch of play in there now so i should be fine. Will let you know!

Sent from my SM-G960U using The Garage Journal mobile app

 

[b.well]

Ok. So not there yet. Socket will not fit in the handle. I reversed the handle until it hit the back nut. Then i turned the hex bolt with an allen key thinking it would tighten up the system. It did a little but not enough. The system stays together a short time then the rear nut lets go. I feel like there should be a 2nd nut in the rear to keep it from moving. Can you see in the back of yours and confirm one nut? Maybe post a pic with a flash shot? Any help is appreciated!

Sent from my SM-G960U using The Garage Journal mobile app

 

[b.well]

vjquan I think I found the answer. Found a helpful calibration video with a torque wrench design like ours. The key is using a pair of needle nose pliers to loosen/tighten the back nut. With the nut loose you can adjust the calibration using the allen key. Once calibrated, tighten the nut.

 

[vjquan]

Yeah, a socket for sure doesn't fit. I guess it doesn't need to be that tight if only pliers can get to it.

 

[b.well]

True that. I used needle nose. The end barley gets over the nut. I didn't feel the nut move at all. But now I turn the handle and everything moves together! Nice. Now just need something heavy to calibrate with. Right now my likely contender is my car floor jack

Does your still have the o-ring under the round head? Wonder what purpose that serves.....hmmmm....

Thanks for all your help!!!

 

[vjquan]

My o-ring is still there, but I don't think it serves any functional purpose. I really highly recommend the digital torque adapter. I use something similar to check calibration on all of my torque wrenches. Hanging a weight to calibrate is just so prone to errors and I wouldn't trust it. With the digital torque adapter, you can test it throughout its entire range and it's also not very expensive.

 

[b.well]

What digital torque adapter do you find accurate? The harbor freight one is $30 plus ship. Mostly good reviews, one guy said it's not accurate, maybe a one off.
https://www.harborfreight.com/12-in-Drive-Digital-Torque-Adapter-63917.html

 

[vjquan]

I have the Craftsman digital torque meter that has long been discontinued. It operates on the same principle just the meter part is a separate unit. I wouldn't hesitate to get the HF if I had to replace it. If you don't have a local HF near by, then I guess you have to factor in shipping, but don't forget about the 20% coupon. If you have other torque wrenches around, you can test the HF torque adapter and see how well it fares. Amazon also has other brands but more expensive.

 

[Provincial]

I got the HF unit a few years ago. Tested out fine. Sat for a year without being used, and then would not turn on. Replaced battery, still no joy. Out of warranty, so I'm out of luck.

I test my torque wrenches against a Bonney beam torque wrench now.

 

[b.well]

Other options I saw are AC Delco(up to 150lbs) and Matco(up to 250lbs). They do not seem to come with the 3/8 and 1/4 adapter like the HF does. Retail much higher than HF and not sure I "need" one. Not a pro shop here just a diy enthusiast. Understandable when torque specs are important so is the calibration of the tool. Haven't found enough reviews of the more expensive models to have an opinion. And of course, sometimes, you get what you pay for