Drift-Pin

Conical bar or pin of steel, used by riveters in boiler and bridge work to enlarge holes which have not been so made in the seam as to come exactly opposite. The taper pin is inserted and driven in by the hammer, stretching the two edges upon which it bears till the two holes coincide. Drifting distre es the metal and puts it under an initial strain if carried to any extent. It is forbidden in most specifications for riveted work.