rowan2•25d ago

Heard a guy at the hardware store say he uses an old truck spring for a knife blank

I was stocking the fastener aisle last week and overheard two guys talking about making knives from scrap metal. One said he pulled a leaf spring off a '72 Ford and got a blade that held an edge better than anything he bought online. Has anyone else tried using salvaged car parts for their projects?

2 comments

2 Comments

the_nina25d agoTop Commenter

That's interesting about the semi truck spring holding up for five years. How much grinding did you have to do to get the arc out of it? Because leaf springs have that curve baked in, right, so I wonder if you're losing a lot of material just trying to flatten it out or if you just work with the curve and shape the blade around it. Seems like a coil spring would be way easier to straighten and cut segments from since they're already round.

piperwhite25d ago

Oh dude that's a classic move. Leaf springs are basically pre-tempered 5160 steel, so they're already heat treated and hold an edge like crazy. I've seen people turn old coil springs into fine blades too, but you gotta be careful because they can warp when you grind them down. The real trick is knowing you don't need fancy steel from a catalog when there's perfectly good high carbon stuff rotting in a junkyard. I've got a buddy who made a camp knife out of an old semi truck leaf spring and it's been his go-to for five years now, still takes a razor edge.