Drillco 350N Series Nitro 21 Piece High-Speed Steel Mechanics Length Drill Bit Set, Black and Gold Oxide Finish, Round with Flats Shank, Spiral Flute, 135 Degrees Split Point, 1/16" - 1/4" in 1/64" increments & 9/32" - 1/2" in 1/32" increments

Drillco 21 piece mechanics length drill set. The Nitro heavy duty 135 degree split point drill with nitride surface treatment, that give a hard, protective layer to the drill (increases hardness without increasing brittleness), which is measurably harder than High-Speed Steel. Body and clearance are black and gold surface treated for maximum lubricity. Recommended for use in stainless steel and other hard metal drilling. High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance. Black oxide treatment adds lubricity and creates small pockets on the surface of the tool that act to hold coolant near the cutting edge. Gold oxide is a thinner oxide surface treatment than black oxide typically used to identify cobalt steel tools; performance is similar to uncoated tools. These round shank tools have flats ground onto three sides to reduce slippage of the bit when used in drill chucks. When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging.What's in the Box? 21 screw machine length drill bits ranging in size from 1/16" to 1/4" in 1/64" increments and from 9/32" to 1/2" in 1/32" increments

• High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance
• Gold oxide is a thinner oxide surface treatment than black oxide typically used to identify cobalt steel tools; performance is similar to uncoated tools
• These round shank tools have flats ground onto three sides to reduce slippage of the bit when used in drill chucks
• When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging
• 21 screw machine length drill bits ranging in size from 1/16" to 1/4" in 1/64" increments and from 9/32" to 1/2" in 1/32" increments