Usual practice is to drill hole a 'skoch' under size of the rod. Rod is tapered just a bit at the entry end and a thick washer is slipped over rod driving end prior to driving. As the rod now a drift, is driven the driven end is upset and forms a head.

As the drift is driven home the friction fit actually draws the pieces together. Very tenacious fastener. Drawing or removing drifts is one hell of a job. 'Portagee pump' or yard made forked gripper and wedges or a hydraulic porta-power are used. Since drifts are part of the structural members of the vessel any need to remove one later in the vessels life is a big job what with fittings/machinery/interior joiner work. I think you get the picture.

Oh, one other very important thing. Once driving starts DON'T STOP! 99.9 times out of 100 the drift will freeze in the hole and you now have a mess to fix.

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