The straight shank twist drill is mainly composed of a handle and a working part. The guide part of the work department is guided and grinding,and the chip groove is spiral to guide the chip. HSS material is suitable for drilling holes on angle iron,wood,plastic,aluminum alloy and other materials. Color:gold + silver Material:high speed steel Package Contents: 50* silver diamonds (1.0mmx10,1.5mmx10,2.0mmx10,2.5mmx10,3.0mmx10) 50* gold diamonds (1.0mmx10,1.5mmx10,2.0mmx10,2.5mmx10,3.0mmx10) Only 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.