[OP]
Contributor
Not knowing any better, I left my HF small torque wrench (in-lb model) in the drawer for about 5 years, at the 50lb mark.
So, I was reading a thread here and ran across where someone said, more or less, not to do that.
What have I done? Do I need to spend yet another $30?
How can I tell if it is still any good?
Moderator
Yeah, you should never leave them set like that. I don't know of an easy way to check it other than comparing it against another torque wrench. It would cost more than it's worth to have it re-calibrated. I would not trust it for anything critical.
Please help support the Creek.
"It's paradoxical that the idea of living a long life appeals to everyone, but the idea of getting old doesn't appeal to anyone."
Andy Rooney
If it is any consolation, your thread made me go check my little C-man that I use for my carbide inserts. I had stored it as per the instructions but, could just as easily NOT have done that. Thanks!
"A hen is only an egg's way of making another egg".
– Samuel Butler
Member
What was the bottom of the scale for the t-wrench you left at 50? I have a pretty big one and 40 ft/lbs is the bottom of the rang for that one.
Member
I think that is a myth invented by some ocd addled drill instructor wannabe machinist. I bet it's just fine. I've personally never seen one go out of spec from that, as checked by the snap-on guy. I have seen one ruined after a bone head used it for a breaker bar though. Purely circumstantial evidence with bigger ones, but I wouldn't loose sleep.
If you want to check the calibration, a quick rig with a know weight on the end of a lever of know length as moved by the wrench, will be pretty darn accurate. Or go find the snap-on truck.
[OP]
Contributor
Bring my HF to snap on guy? Ha ha
i will leave @ my friends shop tho so *he* can have snap on guy check next time truck is there
Member
With a coupon you can get another at HF for about $10..... It's a good idea to have several around just to check them against each other now and then. Thus far I have not experienced any real problem with leaving them with some torque during storage. I am sure it is not the best for them, but at $10 I just don't worry all that much about it. Heck, using one that is slightly off is much better than using none at all which is what most folks do.
Robert
Contributor
Agreed. We had a scale repair department at work for over 30 years, and they certified our T-wrenches. NEVER did they say that was necessary.Originally Posted by Steve Rozmiarek
Never, under any circumstances, consume a laxative and sleeping pill, on the same night
Contributor
Before I retired, I had a set of torque wrenches that had to be calibrated annually. We also had to take a class in using them. We were taught to reset/release the tension on them each time after you are done using them.
We were also taught to not "reef" on them until you see the correct tension or hear the "click" because overshoot is quite common and the amount of overshoot can be pretty dramatic. Rather, we set the wrench to 1/2 the desired torque, ease on it until that value is reached; complete that step on all related fasteners, then set to the final value and gradually apply pressure to "ease" to the final value on all related fasteners. Finish with all respective fasteners (bolt or nut). Do not go back and check as it usually results in causing over tightening.
A lot of what I just stated was demonstrated during the class with students doing the torquing and then instructors measuring and demonstrating the overshoot or improper values.
While actual torque values are important, IMO, in most cases what is important is equal torque on related bolts/nuts such as lug nuts or head bolts etc.
Torque becomes very important in some cases like the newer CT scanners. Imagine when you are laying on the patient pallet being scanned, there is an x-ray tube that can weigh as much as 350+lbs. and in some cases it is spinning around your body at speeds of 3 revolutions per second..... If that tube comes off at that speed, BAD THINGS CAN HAPPEN. There were torque specifications for every bolt, screw and nut holding every component on that rotating frame.
Torque can be important.
Last edited by Ken Fitzgerald; 12-26-2014 at 8:17 PM.
Ken
So much to learn, so little time.....
Moderator
It's not a myth. Before retiring I worked in aerospace & missile defense assembling rocket motors and payloads. I had 2 drawers full of Snap On torque wrenches ranging from newton meters to foot pounds that were calibrated on a yearly recall schedule. Our calibration lab was NIST certified. If they fell out of tolerance +/- 4% they were repaired or replaced. They can go out of calibration even if well taken care of.
If you are torquing the inserts on a cutting head it's probably not a big deal if it's out of spec a little. If you're assembling a flight termination system it is.
"It's paradoxical that the idea of living a long life appeals to everyone, but the idea of getting old doesn't appeal to anyone."
Andy Rooney
[OP]
Contributor
So, as far as technique is concerned, torque to half the final value, once-when the wrench clicks once, stop and move on, torquing all bolts (of same function). Then repeat process at full torque. Do not repeat pricess a second time on any given bolt
Moderator
What is it you are torquing? Generally, you only need to do step torquing if what you are torquing can deform, for example an engine cylinder head.
"It's paradoxical that the idea of living a long life appeals to everyone, but the idea of getting old doesn't appeal to anyone."
Andy Rooney
[OP]
Contributor
its just the Shelix head/carbide inserts for DW 735 planer..... Looking for rules of the road
Contributor
As someone that calibrates torque wrenches, and the standards they're tested against, to NIST certifications, You probably didn't do much harm to that particular quality level of torque wrench. Relax it, and run it up the scale with some torques a few times to make sure it works throughout the scale.
I have no idea what is on the Snap-On truck, but it's probably a more than adequate, simple torque analyzer. If you can get it checked out that way, that would be pretty cool.
Ken and Bruce are correct. ISA and NIST mechanical standards practices for torque wrenches are to leave them relaxed to the bottom end of the scale. ( We'll leave out the long term temp and humidity requirements though.
You're not trying to launch a space shuttle though, just looking for uniform torquing.
Last edited by Mike Cutler; 12-26-2014 at 7:28 PM.
"The first thing you need to know, will likely be the last thing you learn." (Unknown)
Contributor
Bingo!
Ken and Bruce are correct. ISA and NIST mechanical standards practices for torque wrenches are to leave them relaxed to the bottom end of the scale. ( We'll leave out the long term temp and humidity requirements though.
You're not trying to launch a space shuttle though, just looking for uniform torquing.
For torquing carbide inserts on a Shelix head, it's probably good enough.
Last edited by Ken Fitzgerald; 12-26-2014 at 8:16 PM. Reason: spelling correction
Ken
So much to learn, so little time.....
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