These drill set are made of high speed steel, high hardness and durable in use Each drill has a double end and with standard milling Angle 60 . The is used to make tapered holes for the 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 holding. Prefabricated precise positioning for hole processing, guide the drill for hole machining, so reducing error, hole machining for surface of the shaft and other parts. Material High speed steel color:Silver 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 Drill Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.