| Torque wrench calibration [message #76549] |
Sat, 13 March 2010 14:03  |
Gil Slaw
Messages: 69
Registered: May 2006
Location: Hampshire, IL
Karma: 0
|
Member |
|
|
A quick and easy method that I use for my 1/2 inch torque wrench calibration is:
1. Clamp a 1/2" breaker bar in a bench vice.
2. Couple the breaker bar to the torque wrench with a 15mm 6
point socket. The torque wrench shall be parallel to the
floor.
3. Make a mark on the torque wrench handle 12 inches from
the center line of the connecting socket.
4. Dangle a 50 pound bag of water softener salt from the
marked place your wrench and you now have a 50 ft
pound calibration point
Not quite Mil Spec, but close enough for GMC work.
Gil
|
|
|
|
| Re: Torque wrench calibration [message #76574 is a reply to message #76549] |
Sat, 13 March 2010 22:37  |
bukzin
Messages: 840
Registered: April 2004
Location: North California
Karma: 0
|
Senior Member |
|
|
Speaking of torque wrenches, do I need a good one?
What are some of the better brands you guys are using?
Any votes for Harbor Freight?
Bukzin
1977 Palm Beach
|
|
|
|
|
|
| Re: [GMCnet] Torque wrench calibration [message #76583 is a reply to message #76574] |
Sun, 14 March 2010 06:13 |
GMCWiperMan
Messages: 1248
Registered: December 2007
Karma: 1
|
Senior Member |
|
|
Richard,
As I reported recently, my electronic torque wrench calibrator has never
identified a torque wrench, regardless of quality, as much as 10% in error.
Except for my maybe 50+ year old Snap-On, which has a set screw to allow
easy recalibration; with that done, it's at about 2% accuracy across a
20-150 ft-lb range.
Ken H.
On Sun, Mar 14, 2010 at 12:37 AM, Richard <bukzin@gmail.com> wrote:
>
>
> Speaking of torque wrenches, do I need a good one?
> ...
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Torque wrench calibration [message #76611 is a reply to message #76583] |
Sun, 14 March 2010 11:01 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
I have had a few that I checked that were way off. It is interesting that either they are right on (within 5%) or way off (20% or more). I'm convinced that the ones that are way off got that way by someone fiddling with them.
Note:
Bob Burkitt, Ken Henderson, and I all bought these electronic checkers when they because available. So if you have a torque wrench that you want checked, stop one of us at a rally.
Ken B.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: Torque wrench calibration [message #76613 is a reply to message #76574] |
Sun, 14 March 2010 11:16 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
| bukzin wrote on Sat, 13 March 2010 23:37 |
Speaking of torque wrenches, do I need a good one?
What are some of the better brands you guys are using?
Any votes for Harbor Freight?
|
No, You probably do not. Not for general maintenance anyway. If you are not building engines (you will not believe how high the design load of a main bearing fastener is) or adjusting the bands in an automatic transmission (you would not believe how little they should be tightened to be correct), there is little need. Just always do the last check with a run of the mill combination wrench, the length of that wrench and the strength of your hand will serve as an effective limiter.
Sturtevant and Seekonk, but you don't want them. Even used the least one of these will go for is about 300$ (that is American and each). At one time (I was lucky and sold most of them off) I owned an half dozen preset (click type) and dial torque wrenches. All were maintained certified. That was an investment of about 3k+ in 1980$ (who knows what it would be today), and about another 600$ a year in calibration certification unless one was of or tolerance and that would add to that bill.
No vote at all for Harbor Freight. All they had last time I look at the local were Chinese presets - you might as well guess.
Watch the garage sales and flee markets for old beam type. They can't come out of calibration. It you find one and the pointer isn't at zero, tell the seller it is badly out of whack, but you would be willing to take it for a couple of bucks. When you get it home, bend the pointer back to zero - calibration will be as good as it ever was. (There is a one beer story here that will be saved for other days.)
Do not buy a dial type unless it is real cheap (and I mean REAL Cheap). They are really just a beam wrench in a fancy case with a dial gage that may loose its pointer when a fastener does something rude. They are no more accurate than a beam and have much less sense of humor (the capability to put up with some s**t and not go home).
Exceptions to everything:
As I demonstrated to Nick Chapekis when re-installing a drive axle, a big preset (clicker) is nice when working where seeing a scale is tough (like under a coach). The Harbor Freight tool might be good there. . .
The above are the opinions of a "Very Experienced" engineer (real kind - not the cubical kind) and based on many years of experience some of which was costly.
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: Torque wrench calibration [message #76638 is a reply to message #76574] |
Sun, 14 March 2010 17:50 |
GMCNUSA
Messages: 283
Registered: August 2006
Location: Indianapolis, IN
Karma: 0
|
Senior Member |
|
|
I]Speaking of torque wrenches, do I need a good one?
What are some of the better brands you guys are using?
Any votes for Harbor Freight?
--------------------------------------------------------------------------------
Bukzin
1977 Palm Beach
Chico California[/I]
I have 2 SnapOn inch pounds round dial,1 Craftsman 150ftlb spring bar style and 2 Harbour Freight 1 a 150 ftlb and 1 a 300 ftlb both settable click styles. I have checked all of them this summer by clamping square dr in a bench vice and hanging weight at the proper distance from pivet and they all read very close less than 8%. I have some small balance scale precesion weights to calibrate the inch pounds. The heavier weights I weighed on a calbrated shipping scale. The most important thing with the click style the handle must be turned back to zero when not in use.
Larry Dilk
Indianapolis, IN
76 Eleganza II
Patterson 455,Turbo City TBI,
Just LOVE It!
|
|
|
|
| Re: Torque wrench calibration [message #76642 is a reply to message #76638] |
Sun, 14 March 2010 17:58 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
Karma: 0
|
Senior Member |
|
|
[quote The most important thing with the click style the handle must be turned back to zero when not in use.[/quote]
i was not aware of that.
thanks,
Fred V
'77 Royale RB 455
P'cola, Fl
|
|
|
|
| Re: Torque wrench calibration [message #76653 is a reply to message #76642] |
Sun, 14 March 2010 19:41 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
|
Senior Member |
|
|
Fred
You are right on about that. I learned about setting it back to 0 the hard way. Luckly for me my Co paid to get my expensive torque wrench recalibrated. I carry a cheap harbor freight torque wrench in my motorhome. It came in handy several years ago when I had to replace a head on the road. I had checked the cheap wrench against my good one and it was accurate.
Roy
Roy Keen
Minden,NV
76 X Glenbrook
|
|
|
|
| Re: Torque wrench calibration [message #76655 is a reply to message #76653] |
Sun, 14 March 2010 19:56 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
I have several 150's in 1/2 drive plus one 250 in 1/2 drive. I also have one 3/8" dial type and one 1/4" drive. Of the 150's I have one expensive one and a couple of cheap Harbor Freight ones. They all produce the same results. I see no reason to buy an expensive one for GMC use.
Oh yes, I just remembered I also have one bending beam one that my daughter dug out from somewhere around her a couple of months ago.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: [GMCnet] Torque wrench calibration [message #76831 is a reply to message #76574] |
Tue, 16 March 2010 12:17 |
Rick Denney
Messages: 430
Registered: January 2004
Karma: 0
|
Senior Member |
|
|
Richard writes...
> Speaking of torque wrenches, do I need a good one?
I bought a Craftsman click-type torque wrench in 1/2" drive and 150
ft-lb rating about 30 years ago when I was working as a professional
mechanic. About a year ago, I bought a 3/8"-drive Craftsman of the
same type. They look identical except for size. Both were within
single digits of percentage error when checked on Ken Henderson's
calibrator. Neither had ever been calibrated, and about half the time
I forget to unwind the click set back to zero when I'm done with it.
I've heard that the springs can lose their tension, but my sense is
that it takes more than we realize for this to occur.
Click-type torque wrenches are much easier to use at higher torques,
when putting your face in a position to read the beam scale of a
bending-beam wrench would make it impossible to apply higher torque
values, at least without an assistant. The axle-bolts come to mind as
a case where a bending beam wrench will cause a lot of frustration.
They do require proper technique, which includes easing up to the
click.
Rick "who has had to train most tire-store workers how to use a
click-type torque wrench" Denney
'73 230 Ex-Glacier "Jaws"
Northern Virginia
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
'73 Glacier 230 "Jaws"
|
|
|
|
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
