Tension wrench vs. torque screwdriver for small machine work

I had to pick between a tension wrench and a torque screwdriver for holding down a bracket on a Haas mini mill last month. I went with the torque screwdriver and it held consistent at 15 inch-pounds, but has anyone here had better luck with tension wrenches for repeat jobs?

3 comments

3 Comments

martin.riley1mo ago

Hell, I see it the other way completely. Torque screwdrivers are fine for final assembly but for repeat jobs where you're cranking down the same bolt a hundred times a shift, a tension wrench gives you way more feel for when things are binding or the threads are getting dirty. On that Haas mini mill bracket you're better off with the wrench because you can catch a problem before it strips. The numbers just aren't as reliable if you're cranking fast.

the_terry1mo ago

Is a stripped bolt really that common on a Haas mini mill though? Those things are pretty beefy for their size. I've run a few dozen setups on those brackets and never had a thread go bad from just cranking them down. Feels like we're overthinking a simple job. A torque screwdriver clicks and you're done, no fussing around with feel. Tension wrenches are just another tool to lose or have to zero out. If someone is stripping bolts a hundred times a shift, maybe the problem is the operator, not the tool.

christopherw341mo ago

Tension wrench all the way for me on repeat setups, catches grit before it's a problem.