All About Pocket Knives

What is the best choice for material for backsprings? I have some O-1 that I would like to use,but I'm not sure about the flexibility.

I would think it would work if you heat treat it properly.

I will move this to the Repair Forums where one of the guys who does their own springs (like MM) is more likely to see this.

I think it would work but that comes from my very limited experience. I did make my own knife out of O1 and hardened spring then drew it back with a torch. Seems to have been holding up well. I am sure others will be along to give you a more definitive answer

O-1 can be made to work; I made a number of springs for gun locks from O-1 and they worked well.

BUT I'd suggest going to the real experts: Schrade used 1095, and I have to think there was a reason beyond the lower price of the steel.

Schrade's heat treatment for pocketknife springs was to harden to about 62-65 on the Rockwell C scale by heating to 1450-1480 degrees F, then quenching in 280 degree F oil. Tempering was done with a 2 hour 15 minute heat soak at 680 degrees.

I suspect the next lock spring I make will be from 1095 with that heat treatment.

Good luck! Making even a flat spring like a pocketknife has can take a few tries to get it right.
Jim

Jim, they basically used the 1095 not only because it worked well, but because they blanked the springs out of the same steel rolls that they blanked the blades out of. This way they were the same thickness, they didn't have to go changing multi ton rolls, and they patina'd the same. Spring temper is around Rockwell 45, which is just what you'd get at that annealing temperature. A torch works well to, but you don't want to see any red at all on the 1095 or you'll go too low.

Eric

Eric, I hadn't thought about that aspect of it--that makes sense from a production standpoint. I was looking at it more from a perspective of ease in making springs. Heated oil is easy to do with a cheap deep fat fryer (and they come with a cover to put out the occasional flames!); a 680 degree heat-soak can be done with molten lead.

coffeecup wrote:Eric, I hadn't thought about that aspect of it--that makes sense from a production standpoint.

Boy, does it ever!
At times in the shop it is easy for me to be so engrossed with the technical aspects of a problem that I completely overlook a simple answer that is staring me in the face!

Thanks to both of you for pointing that out, an excellent lesson in not over thinking a problem!

I always use L6 or 1095. the L6 makes a fine spring when made correctly