Torque wrenches

[MillWeld]

I had a bad experience with the clicking type torque wrench. I suspected it wasn't accurate so I put a 1/2-13 bolt in a vise and torqued the nut to 10 ft-lbs and in the process I stripped the nut. Yes - it stripped at supposedly at 10 ft-lbs. I returned it to Advance Auto and bought one a traditional one at Sears.

It's easy to calibrate one. I made a pivoting lever arm with a 3/4" nut at the pivot arm. I can put various weights a known distance from the pivot point, put the wrench on the nut and level the lever arm. The distance(ft) x the weight(lbs) gives the torque(ft lbs). The Sears unit was accurate to within 10% at 65 ft lbs. That's what I needed for my trailer wheels.

 

[varmint]

In the 70's, I had a friend who ran a transmission test facility at GM... he had several Proto torque wrenches at his home, and he gave me one. Seems that the "lunch box" rule was in effect at GM back then: if something would fit in your lunch box, it was "yours". He was a big guy, and had a big lunch box!

I felt a little funny about accepting it, but hey, I needed a torque wrench. He instructed me to always set it a zero whenever it wasn't in use- they had experimented with several wrenches before re-calibration, and sure enough, it made a real difference. I knew bolts, especially head bolts, stretched and were one-time uses when critical, but I can't imagine nuts doing that?

 

[JRobyn]

IIUC, reuse (or not) would depend on the percentage of the bolts or nuts yield strength that it is torqued to. Some assemblies have their fasteners torqued to a very high percentage, like 90%. I wouldn't reuse those.

"Blade"? Aren't old-school torque wrenches usually called "Beam" type?

BTW, the inexpensive Harbor Freight click wrenches are quite serviceable. I have a 1/4" and 3/8" and am soon to buy a 1/2". When I've checked them against my beam type, they are quite accurate.

- Jay

 

[Ford850]

IIUC, reuse (or not) would depend on the percentage of the bolts or nuts yield strength that it is torqued to. Some assemblies have their fasteners torqued to a very high percentage, like 90%. I wouldn't reuse those.

"Blade"? Aren't old-school torque wrenches usually called "Beam" type?

BTW, the inexpensive Harbor Freight click wrenches are quite serviceable. I have a 1/4" and 3/8" and am soon to buy a 1/2". When I've checked them against my beam type, they are quite accurate.

- Jay

The HF click wrenches are all on sale right now for $11.99 with coupon (coupon available on their home page of site).

 

[varmint]

Yep, I thought they were "beam" type, as well.

I grabbed (stole?) a HF 1/2" for $9.99 on sale, to augment my beam type and 3/8" Proto, and although I was suspect, it does seem close enough for torquing wheel nuts and such. For that price, everyone should have one.

 

[Rdr202]

Too small for many tractor bolts. When you read your owners manual, did it not say torque bolt to 200 lb/ft? or 140 lb/ft



1/2" Torque Wrench

Or

3/4" Torque Wrench

 

[SPYDERLK]

Kebo, #6 iis not a hard and fast rule. If it was you would be replacing lug nuts and studs every time you remove a wheel.

400 ft/lbs is not something you are going to do easily. My T wrench goes to 250 ft/lbs and just doing 200 is pretty hard. You should also learn how to correctly use it. For one thing you can't put one of your hands on the ratchet area of the wrench to help keep the socket on the bolt/ nut.

Yes you can and should to avoid the side thrust on the bolt youre torquing and also the head of the ratchet. Quite important with use of deeper sockets which magnify sideward leverage.. - However it must be done right. ... Grabbing it will cause several ftlb error, whereas reacting with the heal of your hand aligned at the rotation axis will prevent much greater error than the minute one inherent in the touch.

 

[GManBart]

I think it's worth the money to buy a better torque wrench if you can afford it....it's something that will last forever with reasonable care. I bought a CDI which is the company that makes them for Snap-On. The Snap-On version looks identical, and the only difference is that the head is assembled in the U.S.

Probably the most important thing to check on new tractors are the loader mounting bolts...you'll probably find several of them a bit loose after a little use. The nice thing is that most times you only have to tighten them once or twice, and they stay put after that.

For most tractor bolts, 1/2" drive 30-250lb/ft is enough:
CDI Torque 2503MFRMH Torque Wrench, 1/2" Drive, Micrometer Adjustable, Metal Handle, Dual Scale, 30' - 250' Lbs. - - Amazon.com

 

[PILOON]

Also I recall seeing in an old SnapOn handbook that there exists an 'extender' or 'doubler' to extend the range of a given torque wrench.
It was like a male/female bar that would be installed between the socket and the torque wrench.
When used (ex) if reading 100 you actually were exerting 200.

While double is easy to compute they also had a 1.5 I seem to recall.