Thread: judging flatness

What is the best way to chek your honing stone is flat from new.Could any one explain what method they use to chek flatness.thank you gary

Rarely if ever will a honing stone be flat from the factory. I few tests?

Take a known reliable straight edge and lay it across the hone with a light source behind you and the stone. Do you see light where the straight edge makes contact with the hone?

Other than lapping the stone flat, you could place the stone on a known flat surface (plate glass) then pick it up. If you feel suction....you've got some decent flatness there. Quite some time ago I brought one of my lapped natural stones (finish lapped on a .001" flat DMT D8E) over to a machinist's shop. We placed it on a pink granite grade A surface plate and I was surprised at the amount of stiction.

Just a few ideas for you.

You'll need to get a lapping plate of some kind anyway. Unless you're using diamond plates to hone with, you'll need to lap your stones periodically during normal use.

Chris L

Yep, just press it against a piece of glass or granite countertop and there should be an almost magnetic feel (suction) when you try to lift it up/take it away from the glass/granite.

But you might as well plan on getting one of the lapping methods' components in order to make the hone flat or to just maintain the flatness you may have.