Please educate me on backsprings.

Kevin Cross

Knifemaker / Craftsman / Service Provider
Joined
Sep 13, 2006
Messages
863
I want to try making traditional folders. I see that it is common to use a steel for the backspring that is hardened similar to the blade. My question is this: If titanium can be used as the spring lock for liner locks and frame locks, can it be used for backsprings or back locks?

Thanks
 
I don't believe so. When you temper a spring you are tempering it back to a much softer state than the blade, or "spring temper". I like to run mine between 45 - 48 HRC. Titanium would not spring back to its normal position. Once you preload it it would bend and hold that position I would think.
 
I think that Lionsteel made a slipjoint with an integral handle/spring made of titanium.
 
I know nothing about slip joints, or folders in general.

Will titanium gall when rubbing against steel?
 
Lionsteel and Spyderco have made slipjoints with integral titanium handles and backsprings. I've seen a custom slipjoint that was all titanium (including the blade - maybe Mecha Mecha will know who that was?).

And, as Kevin Cross Kevin Cross points out, lots of framelocks and linerlocks use titanium as the spring.

I think the key is that it has to be Grade 5 titanium (aka 6Al-4V or 6-4), because other titanium alloys aren't particularly springy.

The springiness should be fine, but I wonder about the wear resistance - having a hardened steel tang rubbing on the same part of the titanium seems to me like it would eventually wear the titanium down. On some framelocks they solve this by carbidizing the contact point on the titanium. Then again, I seem to recall that CRK does not carbidize theirs, and they do have a reputation for long term reliability.
 
There's a bit difference between the liner lock liner spring and the backspring in a slipsjoint - isn't that what is meant by "traditional" folder?
 
Back
Top