A tale of testing methods

[scooby074]

Just watched a couple youtube tests of the new Milwaukee 2967.

Something really jumped out at me IRT testing methods. Same tool, drastically different numbers.

Torque Test Channel says 920ftlb max for the 2967 using their method

Shop Tool Reviews says 2000Ftlb with the 5Ah battery, 2400ftlb with the Forged batt !!!

Not really a critique of either tester, just more a curiosity. I suppose as long as the tester's methodology is consistent, the actual numbers dont really matter, but its interesting none the less.

I do wonder if Shop Tool's method of using a Torque Gun to torque a fastener might be a more accurate of real world scenarios. Where does the old Skidmore tester fall in these test numbers? I dont think there is anyone using the Skidmore anymore is there?

Then again, Shop Tools numbers actually overshoot the factory numbers from Milwaulke (1600 Nut Busting), which calls into question STR's accuracy. Torque numbers are really the wild west.

Side note, these monster guns, the Milwaukee and the new Dewalt are going to be socket destroyers. Just nuts IMHO. Really into 3/4 drive or larger territory.

 

[tak1313]

TO ME, TTC's method will produce an overall more accurate and repeatable result, especially for a comparison basis. Seems like there is more potential variation when just using a bunch of torqued bolts - though the more bolts there are, the smaller that variation should be.

That being said, I think I saw in one of the earlier TTC vids that even they say it's not an actual measurement for industry testing purposes, and that they developed it more for comparison purposes (which is what they do).

MY UNDERSTANDING is that the Skidmore is THE accepted industry standard for measuring such tools. I don't PERSONALLY think it's necessarily a more accurate indication of torque power, but like TTC's invention, allows for a reasonably accurate and repeatable means of comparison.

 

[jayemm]

I haven't watched these particular videos, but have watched plenty of others on both channels. The thing I try to remember is that on the Skidmore on the TTC, the 15 seconds ( or whatever time span) in the counterclockwise direction is tightening into INCREASING resistance and is just viewed as max tightening in the left hand direction.
The ShopToolsReview test is loosening into DECREASING resistance and gives a measure of break free capability on a freshly torqued fastener.
I think they both have their merits.

 

[scooby074]

I haven't watched these particular videos, but have watched plenty of others on both channels. The thing I try to remember is that on the Skidmore on the TTC, the 15 seconds ( or whatever time span) in the counterclockwise direction is tightening into INCREASING resistance and is just viewed as max tightening in the left hand direction.
The ShopToolsReview test is loosening into DECREASING resistance and gives a measure of break free capability on a freshly torqued fastener.
I think they both have their merits.

As a mechanic, its loosening that matters most to me. Can the gun hammer a fastener loose? Thats what gets the job done. Thats why I like STR, but his numbers are wacky.

Im assuming his torque gun is accurate to his settings. Just weird how a gun posts torque numbers 3x higher on one test than on another, and even higher than the factory numbers, which tend to be inflated.

 

[WhataTool]

I've had quite a lengthy discussion in the comments with others and TTC even over this. The thing with "busting bolts free" is the thread size, pitch and condition change as you go up and up and he's using larger and larger and different bolts. And there's no way to control for any of that variance. And this is a difficulty with "breakaway" numbers. Breakaway of what? What size? What condition?
You can set up a breakaway bolt with its tension spread over a wide polished/oiled flange head surface and have an M12 break free 1,000 if you want. You'll see this in his testing where a tool will struggle a bit, then he moves onto a larger bolt at HIGHER torque and it removes it right away.

The TTC rig, regardless of whether that's ft-lbs that's relatable to us, is calibrated each day based on known values and other tools its being compared against. If the nut is brand new vs used 5 times, vs has less or more grease, then when it's calibrated it's all back to an even playing field.

And that's why the skidmore isn't used with TTC also has at his disposal, can't be calibrated. You use a set divider number, and the older your test bolt is the more and more that goes out of whack. The less perfect you change and replace grease, the more it moves away from the same tool making the same figure.

IMO if your torque testing method is showing 2,500 ft-lbs on tools few people believe/have seen remove the 1,400-1,600 even the brand is incentivized to stretch the truth on... You dun messed up somewhere. How old are those bolts?

 

[Benito]

I've always like STR's methods simply because it's more relatable.
But he should worry about being pushed into obscurity with these numbers.
Last year he was testing 1" impacts and showing 2,300 ft-lbs. Now he's getting mid 2,000's with 1/2" impacts.
If that's true, why ever watch another review? There are no 2,600-3,000 ft-lb bolts with sockets that fit onto a 1/2" gun. There's no reason to ever look at or buy a new/different impact if that's true because there's no bolts that tight it can work on.

Meanwhile my impact that he shows doing 2K can't remove every Honda crank bolt unless it has a Lisle thick wall socket, so I'm watching more of other reviews lately. A model doing 920 of an advertised 1,100 seems more down to earth and worth comparing than 2.5X what the brand advertises.