PURPOSE: To prevent a slip preventive surface of a working element from wearing out excessively and thus reduce the possibility of the working element's slippage during operation by bonding a coating of diamond particles of a specific particle size to the slip preventive surface of the working element with a brazing alloy.

CONSTITUTION: A slip preventive surface at the tip 12 of a screwdriver is provided with a frictional coating 14 of diamond particles of a particle size from 0.003 in. to 0.010 in. or 0.076 mm to 0.254 mm which is bonded with a metallic brazing alloy including cobalt or nickel at a percentage of forty or more. In this coating, at least thirty-five percent by volume of the diamond particles are surrounded by the brazing alloy.