Zimmer Drill Twist Bone 5inch, Long 0.172inch Diameter Overall length: 5.000 inches nominal Iii part name assigned by controlling agency: drill twist bone 5 inches long 0.172 inches diameter 6s Diameter: 0.172 inches Special features: 4.4 mm dia; 12.70 cm long; for use w/jacobs chuck in all types of drilling procedures