Guhring HSS aircraft extension drills are manufactured using high speed steel for greater strength and rigidity when machining, the 6 inch long shaft allows for deeper hole cutting in substrates such as aluminium alloys, laminated plates and cast iron. Manufactured to a bright finish they are extremely durable and feature wear and heat resistant properties. Features and Benefits High speed steel for greater rigidity and strength when machining Extra long shaft for deeper hole cutting Wear and heat resistant properties extend tool lifespan Specifications HSS Without internal cooling Standards: NAS 907 Web thinning: 1.500 Relieved cone Cutting direction: Right Diameter tolerance: h8 Point angle 118 degrees Typical Applications Drilling Aluminium Steel Cast iron