Tank Products Inc., provides a full line of A.P.I. Tank Bolts and nuts in 3/8" and 1/2" diameters with lengths from 1" to 2 1/2". These fasteners are available in several different finishes, including unplated, black, hot dipped galvanized, mechanical-galvanized and dichromate dipped. A.P.I. tank bolts offered by Tank Products Inc., consistently exceed the minimum strength requirements by substantial margins.