1These center drill set are made of high speed steel, high hardness and durable in use 2Each center drill has a double end and with standard milling Angle 60 3The center is used to make tapered holes for the center of the lathe in order to keep the standard twist drill in place so as to prevent the screw from slipping or deviating 4Used for parts that need to be machined between production centers or work piece center holding 5Prefabricated precise positioning for hole processing, guide the drill for hole machining, so reducing error, center hole machining for the end surface of the shaft and other parts Descriptions: These center drill set are made of high speed steel,high hardness and durable in use. Each center drill has a double end and with standard milling Angle 60 . Used for parts that need to be machined between production centers or work piece center holding Features: These center drill set are made of high speed steel, high hardness and durable in use Each center drill has a double end and with standard milling Angle 60 . The center is used to make tapered holes for the center of the lathe in order to keep the standard twist drill in place so as to prevent the screw from slipping or deviating. Used for parts that need to be machined between production centers or work piece center holding. Prefabricated precise positioning for hole processing, guide the drill for hole machining, so reducing error, center hole machining for the end surface of the shaft and other parts. Specifications: Material HSS color:as the picture Angle:standard 60 degree Size(It includes 2 of sizes) :0.1x 0.3cm,0.15 x 0.4cm, 0.25 x 0.6mm, 0.3 x0.8mm, 0.5 x 1.2cm Weight:121g Package Included: 10 x Hss Center Drill