1/2" x 12" High Speed Steel | Extended Length Aircraft Extension Twist Bit | 12-Pack

Aircraft extension drill bits made from heat resistant cobalt steel for heavy-duty construction application drilling high temperature and high strength alloys. Treated with a bronze oxide for wear resistance and identification. 135° split point design for more rugged and efficient drilling. Made from M42 Cobalt High Speed Steel for excellent wear resistance on high-strength materials. For drilling in medium-alloyed steel, stainless steel, hardened stainless steel, and other heat-treated materials. Available in both 6" and 12" lengths. Type "J" Gold Oxide Finish.