These center drill set are made of high speed steel, high hardness and durable in useEach 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.Material High speed steelcolor:SilverAngle:standard 60 degreeSize(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 1.2cmWeight:121gPackage Included:10 x Hss Center DrillOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.