Case Hardening 4140 question

[FlinterNick]

Working on some lock kits for the Rifle Shoppe.

When case hardening 4140 steel, my temp is at 1450 packed in balsa and coconut charcoaL for 1 hour, is this correct?

At what temperature should I draw back at ? Was thinking 750, but might be too high and would lose the colors.

Much appreciated

 

[Phil Coffins]

Odd charcoal but 375* to 400* F

 

[FlinterNick]

Odd charcoal but 375* to 400* F

its what was available at the local craft shop

 

[LME]

its what was available at the local craft shop

I have never case hardened to get the marbling effect you see on some rifles/pistols . I have for a wear surface only. Charcoal can be purchased at a pet store. I think it is used somehow with fish tanks, I really don't know. It may be worth a try?

 

[Phil Coffins]

A good wood charcoal for case hardening is Royal brand lump charcoal for bbq. I’ve used it by breaking it down to 1/4” pieces and removing as much of the dust and fines as possible. Then mix it with bone charcoal that I buy from Brownells. 1375* F for an hour then drawn at 375* F for and hour gives a hard colorful finish. An 1851 replica I did the receiver, hammer and loading lever.
2015-08-20 001 2015-08-20 001 by Oliver Sudden, on Flickr

 

[FlinterNick]

A good wood charcoal for case hardening is Royal brand lump charcoal for bbq. I’ve used it by breaking it down to 1/4” pieces and removing as much of the dust and fines as possible. Then mix it with bone charcoal that I buy from Brownells. 1375* F for an hour then drawn at 375* F for and hour gives a hard colorful finish. An 1851 replica I did the receiver, hammer and loading lever.
2015-08-20 001 2015-08-20 001 by Oliver Sudden, on Flickr

Do you use distilled water for the quench ?

nice job on the receiver !

 

[Phil Coffins]

Thanks, I use city tap water most of time. Sometimes if my barrel is full I use rain water and it works as well.