When to check torque on rifle screws?

[carlsbad]

This is correct but the screws do stretch when torqued which create tension.
If threads are lubed and properly torqued creates proper stretch/tension and should not come loose

Screws stretch when you torque them. They don't stretch more with use which is what was implied in some of the posts above mine. Action screws are very high yield strength chrome moly steel. To stretch them to 50% yield (which is what I use in the power plant) you'd need 100 to 160 in-lbs, depending on the nut factor (lubrication). But nobody uses that because the threads on the action are generally limiting. You also don't want to put high local stresses on the action creating local bending.

So the action screw is minimally stretched. Still it is enough to keep it from unscrewing. Sometimes when I'm bored I turn the unthreaded section of the action screw down to .210-.220, somewhere around the minimum diameter of the thread. This spreads the stress out over the length of the bolt. Super high strength specialty fasteners are usually made this way. It certainly isn't needed on these bolts but it does allow a little more stretch and a more elastic function of the fastener.

 

[2moreclicks]

Screws stretch when you torque them. They don't stretch more with use which is what was implied in some of the posts above mine. Action screws are very high yield strength chrome moly steel. To stretch them to 50% yield (which is what I use in the power plant) you'd need 100 to 160 in-lbs, depending on the nut factor (lubrication). But nobody uses that because the threads on the action are generally limiting. You also don't want to put high local stresses on the action creating local bending.

So the action screw is minimally stretched. Still it is enough to keep it from unscrewing. Sometimes when I'm bored I turn the unthreaded section of the action screw down to .210-.220, somewhere around the minimum diameter of the thread. This spreads the stress out over the length of the bolt. Super high strength specialty fasteners are usually made this way. It certainly isn't needed on these bolts but it does allow a little more stretch and a more elastic function of the fastener.

I chose your post and stated that it was correct.
The bolt stretch/tension was for the OP and a few others post that I read.
If someone was to torque a second time wait 24-48 hours (relax stage) then torque agin

 

[carlsbad]

2moreclicks, I wasn't arguing with you. Just chose to expand some more. I agree with what you said too. --Jerry

 

[D-4297]

This is correct but the screws do stretch when torqued which create tension.
If threads are lubed and properly torqued creates proper stretch/tension and should not come loose

Not trying to start anything ; but as a former Cold Header Tool & Die guy ( for Aerospace ) a "lubed" screw will NOT torque properly . Under any conditions . To get absolute proper torque value , particularly in inch pound settings , both the screw threads , and the receiving female threads must be clean , and dry . No Lube ! And yes . Screws will stretch , if they are torqued beyond stated value , based on diameter and thread pitch , plus TPI .