Bolt metallurgy question

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Jun 30, 2023 | 06:57 AM

#21

Rounders

Seasoned HDF Member

Joined: Mar 2021

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From: backwoods

Quote:

Originally Posted by Since 1968

I f
We need the bolts to stretch in order to have clamping pressure, d'.

Not my area, but that was my understand with longer bolts, they stretch provided tension. Where and which applications I am not clear. Threadlocker was used more in short bolts for this reason, in the limited reading I did on this once.

In nuke plants for some applications they actually measure this

Jun 30, 2023 | 08:37 PM

#22

piasspj

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Joined: Sep 2007

Posts: 9,208

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From: Central Illinois, Between I-80 and I-74

The bolt stretches in the length between the head and the threads. I don't remember how much I paid for the new bolts but it wasn't much. Cheaper than any of the impulse buy trinkets on the counter.

Jun 30, 2023 | 08:42 PM

#23

Dan89FLSTC

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Joined: May 2008

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From: South Carolina

Quote:

Originally Posted by 2500hdon37s

As has been stated, they're torque to yield bolts.

No, they are not torque to yield bolts.

The reason the factory calls for new bolts is the threadlocker.

Forums are full of posts about reused bolts coming loose.