Bolts- Have you seen this?

[OTmachine]

Crane house. Worked on on conventional, hydro, and tower.

 

[ddillman]

And when the house comes loose, do you think the company is going to warranty them and the damage they cost? I will stick with the torque wrench.

If they sell them for that purpose. I have been involved with crane accidents and they go after everybody even if they are remotely involved.

 

[Flyinfool]

Torque is irrelevant, it is stretch and clamping force that is important. But measuring stretch is more difficult and time consuming, many times impossible. Measuring torque is fast and close enough for most things. Really critical stuff is done by measured stretch. Back when I was building race engines, ALL connecting rod bolts were tightened by measuring stretch. There was a small center in each end of the bolt. You measure the new bolt length with a special micrometer (had pointed ends to match the centers in the bolt) and then after tightening check the length with the mic. The bolts had a specified stretch for proper clamping force. You had to tighten, measure tighten, measure,tighten, measure tighten, measure until it was right. With practice you you knew just how much ugga dugga got close, and just how much more turn to get the need stretch to tweak it into spec.

A very clean and oiled thread will get a much higher clamping force and much greater fastener stretch than will a rust crusty dry old lug nut, when both are tightened to the same torque. Just as a fine pitch thread will give much greater clamping force than a course pitch thread for a given torque.

 

[Charles scozzari]

I'll stick with a torque wrench...

and ARP hardware.