Cold Bluing Steel - Does hardening make a difference?

[Heikki]

Like the title says, does hardening a piece of steel (guard, fitting, spacer) have any impact on the finish provided by using Birchwood Casey Cold Blue? I'm working on a hidden tang and was thinking I'd try that as a finish on the guard and spacer.

 

[Edwardshandmadeknives]

I haven’t done a direct comparison, but I’ve used that stuff on hardened and unhardened steel and never noticed a difference. I use it instead of layout dye sometimes when I want lines to stay for a long time. I don’t know how they “wear” over time.

 

[Heikki]

Thanks for the reply. I have a piece of 4130 that I wanted to try using. Guess I should just experiment a bit, but wanted to see what others may have experienced using it.