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Decalibrated Torque Wrench?
- Thread starter bbs lm-r
- Start date
Seanbev24
Well-known member
It depends on the type of torque wrench.
Yes...
http://buy1.snapon.com/catalog/item...7&group_ID=954&store=snapon-store&dir=catalog
No...
http://buy1.snapon.com/catalog/item...6&group_ID=958&store=snapon-store&dir=catalog
Yes...
http://buy1.snapon.com/catalog/item...7&group_ID=954&store=snapon-store&dir=catalog
No...
http://buy1.snapon.com/catalog/item...6&group_ID=958&store=snapon-store&dir=catalog
Does leaving a torque wrench set to a certain amount for a long time cause it to become decalibrated?
If you leave a clicker type set above zero the spring is under tension, and calibration is likely to suffer.
It depends on the type of torque wrench.
Yes...
http://buy1.snapon.com/catalog/item...7&group_ID=954&store=snapon-store&dir=catalog
No...
http://buy1.snapon.com/catalog/item...6&group_ID=958&store=snapon-store&dir=catalog
But those are the same type, clicker. Unless a different drive size and fixed/flex head make a difference.
These are what I have:
http://buy1.snapon.com/catalog/item...id=954&supersede=&store=snapon-store&tool=all
http://buy1.snapon.com/catalog/item.asp?item_ID=55264&group_ID=954
If you leave a clicker type set above zero the spring is under tension, and calibration is likely to suffer.
Well then, ****...
Seanbev24
Well-known member
No, although the 2nd one I posted is a "clicker", it's a "split-beam" style with a little dial on the side to adjust torque. This style doesn't have to be set to zero.
Seanbev24
Well-known member
The 2 you posted must be set to 20 ft-lbs (3/8") and 50 ft-lbs (1/2") to retain calibration.
Charles (in GA)
Well-known member
This got beat up pretty bad a few months back. Seems the argument drifted to springs in magazines of guns and if they don't take a set, then why should a micrometer torque wrench's spring take a set. The argument just died but never was solved.
Fact is, torque wrench manufacturers tell you to reduce the adjustment on micrometer type torque wrenches, to the lowest setting (but don't go off the scale, that on some, can cause other problems). As far as guns, I have one magazine that was left loaded for a long time, and the spring is so weak, the gun doesn't feed correctly with that one any longer.
Charles
Fact is, torque wrench manufacturers tell you to reduce the adjustment on micrometer type torque wrenches, to the lowest setting (but don't go off the scale, that on some, can cause other problems). As far as guns, I have one magazine that was left loaded for a long time, and the spring is so weak, the gun doesn't feed correctly with that one any longer.
Charles
treasureseeker
Well-known member
I have a Snap on Click Type torque wench which was left for 20 years set to 100 foot pounds and after being checked is still in calibration. I was quite nervous when having it checked. The place I worked at had torque wrenches checked once a year and the mechanics there said the cheaper ones were in specs more than the truck brands but the cheaper ones quickly broke the plastic parts.
4x4gearhead
Well-known member
It's the click type with the knob instead of the conventional ones that supposedly dont have to be zero'd after use.
diesel research
Well-known member
This got beat up pretty bad a few months back. Seems the argument drifted to springs in magazines of guns and if they don't take a set, then why should a micrometer torque wrench's spring take a set. The argument just died but never was solved.
Fact is, torque wrench manufacturers tell you to reduce the adjustment on micrometer type torque wrenches, to the lowest setting (but don't go off the scale, that on some, can cause other problems). As far as guns, I have one magazine that was left loaded for a long time, and the spring is so weak, the gun doesn't feed correctly with that one any longer.
Charles
All of this depends on if a spring is designed to properly handle a specific load or is overloaded. Another example is automobiles. The spring is loaded almost all of the time, except when lifted. The spring only eventually fails due to total number of cycles or being loaded beyond capacity aka overloaded.
Another example would be asking "do you back your rocker arms off when you are done using your car?"
One could argue that if a torque wrench spring is designed to properly handle the load, it will actually suffer more wear from cycling it back and forth between settings. In the real world, that is likely a moot point since it would take a lot of cycles.
I would have to venture to say, in my own experience, neither matters. If it fails while used in prescribed manners, it wasn't very good in the first place. Regardless if that failure was "overload" or "cyclic".
Our norbar stays @ 550ft-lbs except for rare occassions where something like a dayton wheel needs 325 or some locknut needs 300. It continues to pass calibration because it was built correctly in the first place.