PDA

View Full Version : What kind of torque wrench?



vagt6
01-21-2004, 05:42 PM
I need to purchase a torque wrench for general purpose work on my Triumph GT6. I need one with a wide range of settings, but not a heavy duty one. I'd rather not spend a zillion on one, but I do think it's a good idea to buy a decent model that will last.

Here's a link to Harbor Freight's line of torque wrenches: https://order.harborfreight.com/EasyAsk/harborfreight/results.jsp

Which one, in your opinions, would be good for my purposes?

Thanks!

Steve
01-21-2004, 06:22 PM
I would suggest something that will last you.....Armstrong make a good product with a lifetime warranty, (and not as expensive as a Snap-On or a Mac) available from a decent industrial distributor near you. Otherwise, Griot's Garage have one that doesn't cost an arm and a leg.

MGTF1250Dave
01-21-2004, 07:14 PM
The cost of a torque wrench can cover a very wide range of dollars. Usually, the more precise the measurement, the higher the cost. So, I guess it depends on what is good enough for your application. Over time you may also need to have it calibrated to insure the accuracy of the measurement. Depending upon how often you think you might be using it, renting one periodically may be a better solution. A tool rental store most likely will have a calibrated high quality tool available by the day or week.

Safety Fast,
Dave

Paul Johnson
01-21-2004, 10:36 PM
Torque wrenches are only as good as the latest calibration you had done on it. Therefore, if you are not going to spend real money on a good wrench to start with, and calibrate it regularly, then your best bet is one of the beam type wrenches, such as what Sears sells.
Another method, though specifications are hard to find, is angle. The whole purpose of measured tightening is to ensure uniform clamping between two parts. Picture a cylinder head to a block. It needs to be uniformly clamped. If you torque to, say, 50lbft on all of the bolts, but one of the bolts has dirt in the hole, a goofed up thread, or even worse, oil in the bottom of the hole, you'll still get 50lbft, but you will not have the same clamping force at that point. That's why in the aircraft industry, and increasingly in newer cars with aluminum (oh, wait, this is British stuff) aluminium parts, torque angle is the preferred method. But on our old iron stuff, it really doesn't matter that much I suppose.

Dave Russell
01-22-2004, 01:20 AM
Paul,
you have some good points. Correct on the hard to find specs. I don't think that the torque angle specs for old cars are available. I think it would be a lot more trouble than it is worth to research, test, & determine the proper angles for the older cars fasteners. Of course the other application for angle measuring is on torque to yield type fasteners. Not many of them on old cars either.

vagt6,
I have both beam type & click types. I find the click type to be easiest to use since your eye doesn't have to be positioned directly over the scale to read it. A position that is very hard to achieve on some fasteners & a pia always. An advantage of the beam type is that you can easily see if it is out of calibration & correct it by bending the pointer. The beam almost never actually changes its elastic characteristics.

Either type will do a passable job for you. One caution -- Torque wrenches are not very accurate when used below about 20% of full scale. For example - trying to tighten a sparkplug to 15 ft/lb with a 150 ft/lb full scale wrench Could lead to as much as 12 ft/lb error. This simply means that you should use a wrench with a lower full scale for low torque fasteners. You may need to have a 1/2" drive for head bolts & a 3/8" drive for smaller stuff.
D

[ 01-22-2004: Message edited by: Dave Russell ]</p>

vagt6
01-22-2004, 11:20 AM
Thanks, guys, for the great info!

tony barnhill
01-22-2004, 11:24 AM
Dave is right on - I like my beam wrench but catch myself pickng up the click wrench more often than not - &, as usual, Craftsman! I'll buy inexpensive (off brand) tools for some things but for tools that count or that I'm gonna use all the time, you can't beat Craftsman - &, it'd be terrible to buy a cheap torque wrench & ruin an engine!