- A master team on Amazon, which deals only if with the development of tools. We ourselves to using qualitative tools to improve the social status of life. : ? . by the West Germanic PGM drill Association ? . Rock carbide for longer bit life ? . Rock carbide tip carbide surface contact for longer bit life ? . Milled u-flute to reduce bit stress and make the bit run cooler Specification : ? . : drill 's body : Ultrahigh-strength Steel drill 's head : Rock carbide tip ? . : 1/5in ; 1/4in ; 1/4in ; 1/3in ; 2/5 in -LRB- 5 mm ; 6 mm ; 6 mm ; 8 mm ; 10 mm -RRB- ? . number : 4-1/3 in ; 6-1/3 in -LRB- 110 mm ; 160 mm -RRB- Package content : 1 x Tacklife ADC01C cyclic Hammer Drill Bit Sets -LRB- 5 PCS -RRB- 1 * User blue-collar 1 * 24 Months Warranty warm Tips : In order to make doomed your tools for longer tool life, the Drill Bit Sets can not be used for drilling steel.