Cleveland C16744 Taper Length Drill Bit Size 21 Cobalt

Product Description

The CLEVELAND C16744 is a taper length cobalt drill bit designed for demanding metalworking and fabrication applications. Built to Series 2575 standards and conforming to DIN 338, this heavy-duty bit features a 135-degree split point for fast self-centering starts with reduced walking and thrust. The M42 cobalt construction is paired with an oxide gold coating that extends tool life under heat and friction. At 0.1590 inches in diameter (wire size 21), it handles precision hole work across a wide range of materials. Licensed HVAC, plumbing, and electrical contractors, as well as metal fabricators and industrial maintenance techs, reach for this bit when material hardness and hole accuracy matter.

The C16744 is suited for drilling aluminum, brass, carbon steel, cast iron, nickel alloy, plastic, stainless steel, and tool steel. Its parabolic flute geometry improves chip evacuation in deep-hole drilling, reducing heat buildup and chip packing. The straight shank fits standard drill chucks, and the right-hand cut direction is compatible with conventional drill press and handheld drill setups. It is a practical choice for field and shop use wherever a taper length reaches past standard jobber length.

Key Features

• M42 cobalt steel construction for heat resistance and extended tool life in hard materials
• 135-degree split point reduces thrust and self-centers without a center punch on most metals
• Oxide gold coating improves lubricity and resists heat buildup during aggressive drilling
• Parabolic flute design promotes fast, clean chip evacuation in deep holes
• Web-thinned tapered web configuration reduces cutting resistance
• Diameter tolerance held to +0.0000 to -0.0007 inches for consistent hole sizing

Compatibility

Designed as an OEM-style taper length drill bit suitable for standard drill chucks accepting straight shank tooling in wire size 21 (0.1590 inches diameter); compatible material applications include aluminum, brass, carbon steel, cast iron, nickel alloy, plastic, stainless steel, and tool steel.

Installation Notes

A licensed machinist or qualified tradesperson should secure the straight shank fully in the chuck before operation and verify chuck runout before drilling hardened materials. Use appropriate cutting fluid when drilling stainless steel, tool steel, or nickel alloys to maximize tool life. Ensure the workpiece is clamped or fixtured to prevent rotation during drilling. Inspect the cutting edges for wear before each use, as a dull cobalt bit generates excess heat that can harden the workpiece surface.