Page 2 of 2

Re: Pack Hardening 4140 steel

Posted: Fri Nov 05, 2021 9:02 pm
by flatsguide
Patchbox, are those flat head socket screws part of those dowel pins. Nice work.
Cheers Richard

Re: Pack Hardening 4140 steel

Posted: Sat Nov 06, 2021 6:12 pm
by patchbox
Flatsguide,
Yes, the dowel pins are what’s called “pull out dowel pins”. The 1/4” ones are tapped on one end for 8-32 so the 8-32 flatheads are the fastener that is securing them. The screw in the middle that tightens everything up is a 10-32 socket head cap screw. I got the pull out dowel pins from McMaster-Carr. I think the hardness was somewhere between 50-60 Rockwell on the “C” scale. Probably didn’t need to color case harden them but it added a nice touch and improved the wear resistance.

Thanks,

Eric

Re: Pack Hardening 4140 steel

Posted: Mon Nov 08, 2021 8:58 am
by flatsguide
Got it Patchbox thanks I guess the the hole fore the dowel pin is not drilled and reamed all the way through.
Cheers Richsrd

Re: Pack Hardening 4140 steel

Posted: Tue Nov 09, 2021 9:58 am
by patchbox
Correct, one that one block the hole is reamed .2515 and is a blind reamed hole - other side is drilled for a tight clearance for an 8-32 fastener and countersunk.