Calibrated Torque Method 1

[tmgczb]

How to calculate the Torque Values according to pretension of high strength bolts？
For example，high strength bolts，A325, M20, required pretention is 140kN, what is the Torque to be provided?

 

[WinelandV]

For more information, see the "Specification for Structural Joints Using High-Strength Bolts" produced by the Research Council on Structural Connections (

http://www.boltcouncil.org).

If you have a copy of the Steel Construction Manual, there is a copy of the specification contained within.

 

[dik]

is a little trickier if you have slip critical connections.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[dik]

I've never taken a particular liking to calbrated wrenches... the CISC, in Canada, does not recommend them. I actually like the pre-load washers, but don't often spec them.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[dik]

and a man with a wench is even more unpredictable (I couldn't restrain myself).

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[dold]

Pretty much all of the decent sized steel framed buildings i've worked on in the past the erector has used TC/twist off bolts. The bolt has a domed head and a spline at the end of the shank. The "wrench" grips the spline and the nut and turns the nut. The spline is necked down to a specific diameter such that when it reaches a certain torque the spline "twists off" and separates from the shank and presto, your bolt is "properly torqued".

 

[3DDave]

If you can dodge a wrench ...

 

[rb1957]

we have similar ... Hi-Lok and Hi-Lite fasteners, where the collar shears are the "correct" torque. But these aren't meant for high tension applications where you need a high torque (though possibly the tension collars do this).

another day in paradise, or is paradise one day closer ?

 

[jimstructures]

tmgczb,

What code are designing under, as that will determine how they want the torque calculated?

You are getting good advice, please do NOT dismiss it out of hand.

Jim H