Fixing my mistake

MrWhoopee · Apr 15, 2021

Agree with @ericc, if the material you have is equivalent to 4140, it is an oil-hardening steel with a maximum hardness of about Rc 48-50. Pre-hardened 4140 will be Rc 28-32.

"Heat Treatment
AISI 4140 alloy steel is heated at 845°C (1550°F) followed by quenching in oil. Before hardening, it can be normalized by heating it at 913°C (1675°F) for a long period of time, followed by air cooling."

AISI 4140 Alloy Steel (UNS G41400)

Alloy steels are designated by AISI four-digit numbers. They comprise different kinds of steels having composition exceeding the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va set for carbon steels.

www.azom.com

shell70634 · Apr 16, 2021

I made a new one from 4140PH. Came out great. I'm not going to harden as the originals didn't appear to be much harder. If it wears out in whats left of my lifetime I'll be amazed.

Manual Mac · Apr 16, 2021

What exactly is that holder called?
Anybody have a link for it.
I have these that I have made, that work fine, but I like the that you ordered wrong.
Thanks

NC Rick · Apr 16, 2021

shell70634 said:
I made a new one from 4140PH. Came out great. I'm not going to harden as the originals didn't appear to be much harder. If it wears out in whats left of my lifetime I'll be amazed.

That stuff is so nice to machine as well. It wont hardly deflect. Tough one piece chips for me most often though. I like that i have a ready made part when done with carefully controlled heat treating. I doubt the originals are made from such good steel. 1045 or 1050 would work but i hate machining it and my “torch and dunk“ heat-treat system isn’t exactly laboratory grade.

MrWhoopee · Apr 16, 2021

For future reference, pre-hardened 4140 is referred to as 4140QT or 4140Q&T (Quenched and tempered). PH is used for precipitation hardening materials like 17-4PH or 15-5PH. Aluminum alloys like 6061 are precipitation hardening (sometimes called age hardening) but do not use the PH designation.

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Fixing my mistake

MrWhoopee

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AISI 4140 Alloy Steel (UNS G41400)

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Stainless Steel - 17-4PH alloy, FeCr17Ni4 -

Heat Treating Aluminum 6061 - Quenching and Aging Aluminum 6061