Why would my Benchmade knife have such poor edge retention?

[Bigfattyt]

You should hope so. The wrong belt grinder can ruin the heat treatment, permanently ruining the knife. Unless a belt grinder is specifically suitable for sharpening knives, it is not for sharpening.

Another common mistake around here (Edit: By which I mean the Netherlands) that ruins knives is the use of the spinning stone wheel (I forget the exact english term). That'll mess up your knife right quick.

I hope OP got spared the permanent damage.

This is a perfect example of why cheap is often more expensive.

Spinning stone wheel typicallynis a bench grinder. I have one with a stone wheel, and other side is a wire wheel.


It spins much too fast to sharpen on without ruining the heat treat.

There are stone wheel systems that run slow, with coolant which are ideal.

Speed kills when it comes to sharpening on power tools.

I have a 2x72 belt sander. Single speed. Very fast. I will do light, quick passes, with a dip in cold water every pass. It is still a possibility to absolutely destroy an edge.

I will set the bevel quickly, then refine/finish without power tools.

If I had a vdc, and could slow the speed way down, I'd have no issue with using it more for sharpening.

 

[DMG]

Op, buy a Spyderco Sharpmaker and learn to use it. Don’t let the clowns with high speed abrasives touch it again.