hardening the tip of a titanium lockbar

[peter r]

title says it all, i want to harden the contact pont of my lockbars, how should i go about dooing this?

 

[Frank Niro]

Just heat them to red and let them air cool. Frank

 

[Daniel Fairly Knives]

I think some people use a carbidizer for this but I'm not sure.

 

[butcher_block]

they also work harden a bit so i put an undersized stop pin to make sure the Ti is on the lock face and spine wack it a while. then replace with to spec parts and not worry much about lock over travel

 

[stevenkelby]

I think some people use a carbidizer for this but I'm not sure.

I've recently read on USN posts by Hinderer, Mayo, Ken Onion, Strider and Scott Cook that they all use a carbidizer on the Ti lock face, one of these:

http://www.travers.com/product.asp?...ass+level3+id+28731&eaprodid=37061-57-101-000

Also a great post by Ken Onion about frame lock fitting:

I use a carbidizer and sometimes I'm a tip burner but as others have said nothing is a substitute for proper lock fit and geometry. Liner locks and frame locks are arguably the easiest locks to make .But the most difficult to make right . Many makers file fit the lockbar which is a big no no. Build a fixture and fit your locks properly . Bob T has a book out in which he goes over in detail proper tools and geometries which is helpful.
I calculate degrees of neutral and degrees of engagement based on the length of the lock bar (radius)to figure ramp angle on the tang . Then I make the contact area of the lock as far away from the pivot as possable to limit the amount of compound leverage against the lock bar . Radius the leading edge of the lockbar slightly and include 1/4-1/2 degree lead on the lock face . You should have at least 1/8 " contact surface and not more than 3/16 contact on the average size folder .

Another big no no is using a round dowell ( stop pin) and a flat tang combination as the area of contact is minute .Your tang should have a radius the same as your stop pin so as to have a much larger contact area . Otherwise the lockbar you so painstakenly fit will move in time and defeat or have slack in it as a result of the tang slamming into the stop pin and hammering a flat spot in the stop pin . Just make sure if your using a round pin the radius the contact area for maximum contact .If you use a full backstrap .Make sure your area of contact is maximal also and you place a line up (spring pin or dowell pin) in it to absorb the impact of the blade as oposed to relying on the backstrap screws to absorb the impact .

If the proper ammount of thought and precision and fit goes into the critical triangle ( pivot,lock and stop) the knife will work well and last for generations . (Also make sure your parts are flat,flat flat !)With or without the carbidized ,or burning the lock tip. Those should only be used to slick up the action a tiny bit .

 

[peter r]

i also angle my lockbar to be as far from the pivot as possible. and when i grind the angle for the contact into the blade i use a rough belt and position the hatches at a 45 degree angle so that the striations dont faciitate disengagement. and the carbidizer seems to be the way to go. i think ill try it.