Gearhead Jim

Not many places want to do it unless they made the wrench, and some of them charge almost as much as a new wrench itself. In addition to the wait.

Suggestions?

KX

may I ask you why you feel the need to do this?

07atomic

Find a snap on tool guy they have a torque gauge on there truck they can check it for you to see how accurate it is.

KX

Why bother a Snap On guy. Just get a second wrench and compare one to the other. Honestly, I sold Proto tools for 10 years and never encountered an off torque wrench, never. Now if you are talking some lame China made beam wrench, well, just toss it out and get a new one!

R&L's C6

That darn axle nut is causing you a lot of headaches ain't it...

Jeff78

That is what I do with our wrench at the shop.

Allen_B

Take it to SWFLANT.

Nevermind, this isn't nuclear weapons so they likely wouldn't have it in the CAL run...

<Sorry, poor Bubblehead joke >


/r

Allen

Rogers 07

A good way to check is to tighten a bolt or nut to about 70% of the torque wrenches upper limit, (make sure the fastener is capable of taking the torque) then carefully mark the position of the bolt head. Assuming you are using ft/lbs, use a second torque wrench, Set it at about 20 lbs less, check the bolt, then increase the torque setting 5 lbs at a time until the head of the bolt just moves a little bit, If you are within +/- 10% of your original torque setting the wrench is OK

Bill Dearborn

Not sure how you knew the wrenches were accurate without being able to compare them to a standard traceable back to NIST. If you can't do that you don't know which tools are accurate and which aren't. High quality has nothing to do with whether or not a tool has been calibrated. It could affect how long a tool can be used on a regular basis before it require recalibration but that is all. If you work in an industry that requires calibrated tools you will find calibrations are usually done on a 6 month or yearly basis with the tool being considered unusable until it has been certified or recertified by an appropriate calibration lab. Mechanical torque wrenches that I saw being used in manufacturing were typically on a 6 month calibration schedule.

Bill

KX

OP did not state why he need to calibrate. I mean, if he is only doing lug nuts, whats the big deal!? Now if he is needing inch lbs and must have total accuracy, sure, have it calibrated! He must have a reason for suspecting an issue....

07atomic

I just suggested this method seems to be the easiest way for me. My snap on dealer has one on his truck and checks my guys all the time but that's just my opinion and you guys know what opinions are like!!!!! This is what I'm talking about http://buy1.snapon.com/catalog/item....re&dir=catalog

johnodrake

Try this Bill

Wayne O

You used to be able to send a Craftsman Microtork torque wrench back to be refurbised and recalibrated through a Sears Repair Center for a reasonable cost ($40 comes to mind). Several years ago, 2 of my 3 Craftsman Microtork wrenches broke at the locking ring and leaked. By the time I took the 2nd one in to be fixed Sears had closed down their local Repair Center. I went back to Sears and was basically told they don't fix them anymore.

Do a search if you want.....there are places that repair and recalibrate torque wrenches but in my case it was almost as expensive as buying a new torque wrench. I did buy a new, replacement torque wrench (and it wasn't a Craftsman).

BackInBlack05

I've calibrated 1000's of torque wrenches in a former life. My fav was the old Protos with good scale and linearity adjustments. But I can also say a lot were out of spec. Never encountered an off torque wrench? I find that hard to believe.

Johnodrake posted the best "home method" providing you have weights or a force gauge (calibrated scale).

OP, yeah a Cal lab is going to be expensive compared to an economical wrench. A 3-point check with no adjustments or certification could be considerably cheaper if you can find a cal lab offering that. The Snap-on truck would be a good option.

Carsonvette

I am a Metrologist in Aerospace, I calibrate tools for a living. All torque wrenches need regular checks to insure they are in calibration. How often depends on how often it is used and quality of construction. If it has been dropped it should also re-checked. I would never trust a torque wrench that has not been calibrated. That said, if you use a quality Calibration lab you will pay about what a new Torque Wrench is worth.

GOLD72

I treat mine like a surgical instrument. It is stored in its case and kept in my master bedroom closet. Never used as a wrench to remove bolts & nuts and always stored at 20 ft-lbs setting.

tim414

been there, done that

tim414

I use to take care of these chores for the military when I was in Nuclear Weapons (in the service).

They ARE delicate instruments which REQUIRE calibration checks/corrections intermittently. We always stored ours on zero. However, for tactical nukes, we might not get the luxury of keeping the torque wrench in climate controlled conditions if deployment were underway. But, for critical torques we had a instrument which would validate the wrtench before the critical torque value.

But YES, torque wrenches DO get knocked around and require calibration.

Carsonvette

A Torque Wrench should be set to "zero" when not in use.

Johnz02Z06

Check out this video....I am going to do it this way. Even if it is off then you know by how much.