Button lock questions

[Setarip]

I have a couple of questions for those who have made knives with button locks…

1. How critical is the hardness for the button itself? I’m currently prototyping and making my own buttons, but there is very little information out there about hardness. For example, grade 5 titanium works quite well with liner/frame locks, but would it be suitable for a button lock?

2. If titanium is not acceptable, would something like 440c at around 40-45rc work? Ti connector sells buttons in the mid to high 50’s, but I’m not sure I can machine the button post heat treat. And frankly, I’m not sure what treating after machining will work well either since these are very small and thin parts.

Any insight would be appreciated!

The link is to a photo of a practice button I machined out of annealed 440c
https://drive.google.com/file/d/1LRT3kQ7VbRf49H2sNSm_kIJ82m1TYDKS/view?usp=share_link

 

[DevinT]

My twin brother Darrin makes button locks, he hardens all of the bearing areas, liners, buttons, blade, of course.

People will fidget with a knife until it wears out, so he says everything should be hard.

However I see lots of button lock knives made with titanium and aluminum frames.

Hoss

 

[Setarip]

Makes sense to me. Question is…how hard to make the parts? Currently using my Pro-tec to reverse engineer the concept. It has aluminum scales only and I’m assuming a hardened button. Fired many many times with no major wear. However I bet it certainly has a life expectancy with aluminum as the frame for the components.

 

[Stacy E. Apelt - Bladesmith]

I would make the button the same hardness as the blade it locks into. Also, the liners it goes through should be stainless or titanium. Soft liners like brass and aluminum can wear into oval holes.

 

[Setarip]

Thank you for the advice! I’m still in the design phase. Just heat treated the prototype button and it survived with no perceivable warping. I’ll probably keep the button close to the blade hardness, if not the same.