Alvin I finished my roller gate a few months back and used step bit a lot on 11 gauge. 2x2 square tubing to bore rosette weld holes in it when I was piecing shorter sections together with internal bracing. Very useful.
R-Bo
1959 Apache 1/2 ton Big Window, Short bed Fleetside (under reconstruction) 1966 GMC 305V6 in the family