DISSTON COMPANY 571299 MM 7/16x5-1/2 COB Bit Master Mechanic, 7/16" x 5-1/2", high speed steel with cobalt drill bit, 135 split point, jobber length, 3/8" shank, 135 split point design with 4 cutting edges allows quick penetration eliminates walking, 8 percent cobalt content provides heat resistance delivers maximum cutting efficiency at temperatures in excess of 1000 degree Fahrenheit, recommended for drilling in hard metals such as heat treated steel, stainless steel, chrome, manganese steel Plus titanium Armor plate, Carded. Features Double reinforced with industrial grit glue for increased life durability Easy to use Manufactured in China USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.