an interesting comment on using or not using the Tormek wheel to flatten blades

[Herman Trivilino]

Now that I think it about it some more, I guess I have been polishing the backs of my chisels.  It's part of the process for removing the burr.

Elden, I too had the same experience with hammering a chisel.  I never thought of using a chisel without without a hammer.  But when I started sharpening them on the Tormek I saw that that was actually the proper way to use them.  A sharp chisel completely changes the way you think about mortising for a hinge, for example.

[Rob]

in the final analysis....just think of those electron microscope pictures of sharp versus dull edges in Lee's book.

IF.....you want fabulously neat and crisp edges to your work then the line of metal that makes up the edge MUST be a perfectly crisp line.  If you leave the factory grind on the back and only sharpen the bevel, it literally leaves serrations in that line....it would look like alternate hills and valleys close up.  By flattening the back (to a polish for the perfect finish) you remove those hills and valleys and of course you cant remove them by sharpening the bevel only.

I guess most people only imagine that a blunt edge is caused by the apex being rolled over...not that a virtually invisible series of scratches on the back could have any impact at all.

BUT....its all degrees of course....for framing...dont waste my time...(I can hear the foreman shouting :-)