Micro 100 QTH-606L Boring & Grooving Bar Holders; Inside Diameter (Inch): 1/4 ; Inside Diameter (Decimal Inch): 0.2500 ; Outside Diameter (Decimal Inch - 4 Decimals): 1.2500 ; Outside Diameter (Inch): 1-1/4 ; Overall Length (Decimal Inch): 5.8000 ; S