Micro 100 THMA-716 Boring & Grooving Bar Holders; Inside Diameter (Inch): 5/16 ; Inside Diameter (Decimal Inch): 0.3125 ; Outside Diameter (mm): 16.0000 ; Overall Length (mm): 69.8500 ; Overall Length (Decimal Inch): 2.7500 ; Overall Length (Inch): 2