Drill America #39 Cobalt Drill Bit Set - 12-Piece DWDCO Series for Metal, Wood & Plastic Drilling - High Speed Steel Drill Bits for DIY & Professional Use

Drill America DWDCO series Qualtech economy cobalt steel reduced shank drill bit. Made of heat resistant cobalt steel and ground to a heavy duty 135 degrees split point. Common flute and overall length for minimal adjustment during tool changes. Precision ground for high degree of concentricity between shank and body diameter. Ideal for drilling in tough, high tensile strength materials.

Cobalt steel tools are similar to high-speed steel, but with more cobalt for improved performance when cutting harder metals such as stainless steel or nickel alloys

Gold oxide is a thinner oxide surface treatment than black oxide typically used to identify cobalt steel tools; performance is similar to uncoated tools

Round shanks allow use with a wide variety of toolholding systems

When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging

Ideal for drilling in tough, high tensile strength materials