Abstract: A method of making a cutting edge, which comprises coating a substrate cutting edge having a defined cross-sectional geometry, with a material which is harder than the material of the substrate cutting edge by a vapor deposition or sputtering process, if necessary in the presence of gaseous or vaporized molecules of another element or a compound of another element where it is desired to form the coating of a compound, at a pressure of less than 10.sup.-2 m bar, while simultaneously subjecting the cutting edge to ion bombardment with ions of sufficient mass and energy to cause sputter removal of the deposited material at a rate which is less than the rate of deposition, whereby a cutting edge formed of the deposited material and having a defined cross-sectional geometry and ultimate tip radius, is obtained.

Abstract: A razor blade edge tip has a cross-sectional shape defined, over up to 40 .mu.m from the extreme edge by the equation w=ad.sup.n, in which w is the tip chord thickness in .mu.m at a distance d from the extreme edge; a is factor of proportionality not greater than 0.8, and n is an exponent having a value in the range 0.65 to 0.75.This results in a tip shape which is relatively thick very close to the edge but whose overall cross-section is narrow, compared with known tip shapes.