Bosch HCBG24T Blue Granite Hammer Drill Bit 7/8 x 4 x 6""BOSCH" HAMMER DRILL BITS Size; 7 8" x 4" x 6" Milled u flute and deep cut single flute designs combined with a diamond ground carbide tip to provide fast removal of drilling dust Perfect "on center" diamond tip grinding for fast starts and drilling Inductive hardening process provides a softer shank for better gripping power Drill bit is used for fast impact drilling in concrete, stone and masonry.