Harden lockbar on lockback?

[Nylund knives]

Hi!

I'm working on my first lockback and would appreciate some input.

Do the locking bar need to be hardened and how hard do it need to be, can I only harden the tip of the locking bar and leave the rest soft so I can do some filework or inlays into it?

What hardness is suitable for the spring? The locking bar and spring is made in 440A.
My plan was to heat treat it to about 50 hrc wich I can reach with a temepering temperature of 550°F if I want it softer I need to go up to almost 1000°F wich I would like avoid.

Jakob

 

[Frank Niro]

This much I can tell you, and that is 50RC is far to much for a spring. Frank.

 

[paps]

I harden and temper my lockbar the same as the blade and use already tempered spring steel or titanium for the spring.

 

[KenH]

Interesting info at the following link showing 1095 blued tempered spring steel at Rc 48 to Rc51 range.
http://www.tmtco.com/products/spring-steel.html

Since it shows 1/8" as max thickness, perhaps the Rc range is due to the thickness?

Ken H>