Check the listing for details. 18.5mm HSS 6542 Reduced Shank Drill Bit. Condition: New. Listed at 10.92 USD. Reduced Shank Drill Bit General Information：[1]Please Note: To make clean and precise holes, water is required for lubrication and cooling when drilling metals. Increased use of water lubrication will extend drill bit life[2]Reduced Shank - Expanding the size range capacity of a portable drill chuck. Common flute and overall length for minimal adjustment during tool changes[3]Black Oxide Finish - Black oxide treatment adds lubricity. Small pockets on the surface of the tool that act to hold coolant near the cutting edge[4]Wide Application - Design for drilling in low and medium tensile strength materials, such aluminum, iron, copper, brass and metal[5]High Speed Steel tool - 18.5mm cutting diameter. Good for most general purpose applications, featuring a combination of hardness and toughness for wear resistance.