When drilling hard steel watch pinions, commence with a hard and sharp drill, and drill a little way only; then, before it ceases cutting, withdraw the drill and resharpen it, and so on until the hole is deep enough. On no account keep on drilling tor a single revolution after the drill ceases to cut, but constantly re-sharpen. It is principally the backward and forward motion of a bow that causes the bottom of the hole to "glaze" when drilling tempered steel; consequently a watch lathe in which the motion is always in one direction is better. While a drill retains its cutting edge the work will not glaze. Having got the work glazed, the .surface can be roughed by a piece of brass wire into which fine emery or oilstone dust and oil has been hammered at the tip end. Use the brass wire as a drill for a minute or so, then thoroughly clean out the hole and commence again with a sharp drill.

Ready-made drills are generally too soft to cut watch pinions; they have to be rehardened by heating the blades only in a flame and rapidly withdrawing them with a sudden jerk. This is called "flirting" them, and the sudden cooling in the air effects the hardening. Sharpen them before using, and lubricate with turps. Occasionally a pinion is found too hard to be drilled even by this method; it then has to be lowered to a blue temper.