Drilling in metal takes tough bit. Some bits make it through once and then you throw them away because theyre too dull for a second go. Silver and Deming bits youll reach for time and time again and are great for plowing through extended drilling projects. A special fluted design clears out debris and dust for optimal cutting contact and faster drilling. High Speed Steel construction takes on hard carbon allow steels, cast iron, wood, plastic and more. Size: 3/4 by 6-Inch .