How to tell if your carrier key is properly staked.

[DBR]

A few points:

1) The stress in the screw that results from a particular torque value depends a great deal on the condition and lubrication of the mating threads. Most screw company torque specs require clean, lightly oiled threads.

2) It is important not to exceed the maximum recommended torque because you want to keep the stress in the screw below the "proportional limit" of the screw's alloy. Think of the screw as a very stiff spring you are preloading; if you over stress it, it may actually have less tension even though it may not break.

3) Most high end screw manufacturers like SPS, Allen, Unbrako and others supply their own wrenches for their Allen head screws. The wrenches are designed to fail before the screw head strips. Therefore you have to specify a maximum screw removal torque to insure the screw comes loose before the wrench fails, assuming you want to remove the screw by nondestructive means.

This information was obtained by me from the above referenced screw companies when I did design work involving critical applications of their fasteners.

[Clobbersauras]

So what's your guys opinion of this staking job? So far I have about 3500 rounds through it on an SBR.

[Tweak]

I'd check the torque and stake to standard, more from concern over losing a head from a screw than from loosening.

[JSantoro]

I'd have a greater warm-fuzzy over the material of the BC being pushed into the splines on the screw head, where it's engaging a textured surface...instead of the material of the screw head being pushed outward onto the smooth surface of the walls of the hole in which the screw goes.

I'd also re-torque and re-stake to the standard.

[markm]

So what's your guys opinion of this staking job? So far I have about 3500 rounds through it on an SBR.

might be just fine... but it seems to me the wrong part got smacked. You want the key material bent into the screw... not the reverse.

[Heavy Metal]

I would counter-stake those punches on the counterclockwise sides of the punch marks displacing metal from the key into the screw, just a hair below the original punch marks. You are basically trying to make a 'stop' for those spots to keep it from unscrewing.

[Tweak]

I've seen that method before but that's the first time I've seen (assuming here) that the socket wasn't deformed so that a wrench wouldn't fit.