What is a drift pin?
A drift pin is a tool used in structural steel and metal construction that enlarges, shapes or aligns the hole.
More in depth definition of a Drift Pin
Drift pins are tapered and can be constructed from wood, light alloys, copper, or steel. The most common use for a drift pin on construction projects is to localize a hammer blow in order to align two bolt holes in separate structural steel components that are designed to be aligned.
Example of a Drift Pin Being Used
If you’re installing a structural steel member on a gusset plate you would swing your structural steel member into place with a crane and align the holes on the structural steel as closely as possible to the holes in the gusset plate. Odds are your holes will be off by a small amount. This is where the drift pin comes in handy. First you select a drift pin that is just slightly smaller than the two holes that you’re aligning, then when you’re ready you set the drift pin in one of the holes (either the gusset plate or the structural steel member), and apply a hammer blow(s) until the drift pin slides into the second hole. Once the holes are aligned you can add a bolt, rivet, weld, or combination of the three and then slide the drift pin out of the aligned holes.