Fast Impact drilling in concrete, stone and masonry. Low voltage, high temperature brazing prevents carbide cutting edge from breaking out even when heat builds up during deep drilling. Milled U-flute and deep-cut single-flute designs work with the diamond ground carbide tip for fast removal of drilling dust and increased drilling speed. Perfect on-center diamond tip grinding for fast starts and drilling. Includes: Blue Granite 8-Piece Carbide Hammer Drill Bit Set - HCBG800, (1) 3/16 x 4 x 6 Bit - HCBG04, (2) 1/4 x 4 x 6 Bit - HCBG06, (1) 5/16 x 4 x 6 Bit - HCBG09, (2) 3/8 x 4 x 6 Bit - HCBG12, (1) 1/2 x 4 x 6 Bit - HCBG16, (1) 5/8 x 4 x 6 Bit - HCBG20.