- Ironton Titanium Drill Bit Set - 63-Pc. 21 drill bits in commonly used sizes from 1/16in. to 3/8in.: 1/16in., 5/64in., 3/32in., 7/64in., 1/8in., 9/64in., 5/32in., 11/64in., 3/16in., 13/64in., 7/32in., 15/64in., 1/4in., 17/64in., 9/32in., 19/64in., 5/16in., 21/64in., 11/32in., 23/64in., 3/8in. 41 replacement bits: (18) 1/16in., (14) 1/8in., (6) 3/16in., (3) 1/4in. Storage box is indexed to help you find the right bit quickly Replacement bits are packed in 4 storage tubes