Metal drill bit professional set 1-1.5-2-2.5-3-3.5-4-4.5-5-5.5-6-6.5-7-7.5-8-8.5-9-9.5-10mm. Used to drill in all type of metals like iron, soft steel, cast iron, bronze, etc.. Built with special steel are highly durable and provide a quick and precise drilling. Resistant to overheating during intense drilling in metals. Punto with the high quality and durability.