Blade warping

[alexkuzn]

My blades tend to warp a little when I grind. Yesterday I tried to grind 1/4" and it also warped a little. I am getting an arbor press so it'll be easier to straighten blades. I don't know may be with arbor press you can straighten blades easily but without I find it almost impossible to have a perfectly straight blade. I am using a granite surface plate to check for flatness.
How much of warp is acceptable? For some of my blades I can see any warp by naked eye but if I put it on granite plate it's more obvious(it's less than 1/16" for 12"-15" blade).

Am I been a perfectionist?

Thanks,
Alex

[Ray Rogers]

Nothing wrong with being a perfectionist. The less warp, the better.

If your blades are warping during the grinding then you need to be careful about several things:

1) Don't let the blade get too hot. grind bare handed so you can feel the heat - if it's too hot to hold, it's too hot. Dip the blade in water every few seconds to cool it down.

2) Grind a little from one side, then switch to the other side. Don't try to completely grind one side at a time.

3) Use good blade steel purchased from a reliable supplier. Such steel is expected to be completely annealed and will grind more evenly. If you are grinding 'salvaged' steel and haven't managed to get it properly annealed then the stresses that may be in that steel due to it's original use will cause warpage as some of the steel is ground away.

A well annealed piece of steel that is straight when you start should produced a straight blade when ground according to these directions ....

[fitzo]

I'd add, don't push too hard. You can easily bend a long blade grinding annealed steel.