Mr. KG, the small sharpness improvement caused by the copper-roller is a riddle for me. Your idea that the tiny groove in the roller surface may cause this improvement is very interesting.
I would be interested to know if a lead roller will behave similarly. Lead is less hard than copper and so the depth of the groove should be greater and micro-deburr grater part of the apex. This, in my thinking, may cause farther improvement of the BESS score.
Jan
P.S.: On this occasion, I have remembered recommendation for scissors blade deburring form Tormek handbook. See the attached figure.
I would be interested to know if a lead roller will behave similarly. Lead is less hard than copper and so the depth of the groove should be greater and micro-deburr grater part of the apex. This, in my thinking, may cause farther improvement of the BESS score.
Jan
P.S.: On this occasion, I have remembered recommendation for scissors blade deburring form Tormek handbook. See the attached figure.