ER collet torque

[darkzero]

Just looked it up. 130 ft/lbs for ER-40. Mari Tool says 15% less for bearing nuts. That's still 110 ft/lbs. I doubt I'm getting even close to that using 2 wrenches with no chuck holding fixture.

MariTool

www.maritool.com

The following torque ratings are for solid ER style collets nuts. Bearings collets nuts are not as strong so reduce these values 15%

When clamping on shanks 30% smaller than collets maximum capacity, reduce torque value 40%.

 

[darkzero]

The problem with applying torque is that most adapters are made to fit an exchangeable head type torque wrench. These are common in Europe but not common here so they are expensive to purchase. You can use a standard square head torque wrench with a crow's foot if you can find one in the right size for hex-shaped collet nuts

I suppose the reason why they don't commonly sell adapters to be used with a common square drive torque wrench is the accuracy. When you add an accessory like a crow's foot the crow's foot should be oriented 90° from the handle so it doesn't alter the length much at the point of rotation to get an accurate reading.

So if you were to just use the adapter pointing forward or any angle other than 90° the torque value will not be accurate. I wonder how much the torque value will vary & if it is even that much of a difference. I remember learning about torque wrenches & crow's feet in auto shop courses at an adult center but that's about it. And that was like over 20 yrs ago.

I'm sure there is a formula for calculating the variance. This is dejavu & I feel like we have talked about this here before. I even remember searching for those square drive adapters & only found them in the UK or Germany. A diagram similar to this is also familar.

 

[mikey]

Yup, you can use a crow's foot at 90 degrees and it will be accurate. Problem is finding one that fits your ER nut and also fits a square drive torque wrench.

 

[Aukai]

I learned something, and have a plan, thank you....
Necessity is the motherhood of butchery....

 

[higgite]

Of course I torque them. Who doesn't? I just don't know how much. Probably, one GG on the Darkzero Scale. Of course, that's one old GG. You might even call it one GGG (Geezer Gorilla Grunt). We geezers have to be careful how hard we grunt, if you get my drift.

Tom

 

[Cadillac]

German spec is good-n-tight.

 

[Firstgear]

You guys make me laugh! Thank you!

 

[Norseman C.B.]

I use one URRF or two depending on the situation ...........

 

[pstemari]

I suppose the reason why they don't commonly sell adapters to be used with a common square drive torque wrench is the accuracy. ...

So if you were to just use the adapter pointing forward or any angle other than 90° the torque value will not be accurate.

The adapters typically won't fit on a square drive torque wrench. They are straight, but the ones I've seen have a special tang that goes directly into the torque wrench.

One could always measure the length of the handle, and then come up with a weight to hang from it to get the appropriate torque .

Sent from my Pixel XL using Tapatalk

 

[darkzero]

The adapters typically won't fit on a square drive torque wrench. They are straight, but the ones I've seen have a special tang that goes directly into the torque wrench.

Yep. These are the ones I was referring to in that post that aren't commonly found.