Norseman Type 166 Aircraft Extension 7/64 in. x 6 in. Twist Drill Bit is designed for durability and precision, featuring a black oxide surface treatment that helps prevent chip welding and enhances abrasion resistance. This heavy-duty drill bit includes a 135° split point tip, allowing for faster drilling and efficient chip ejection. It is specially crafted as a high-speed aircraft extension drill, making it for drilling holes in hard-to-reach areas with ease and accuracy. Model Number: 68490