Kennametal 4150257 Drill Bit 21/64 in Solid Carbide 140 Deg

Product Description

The KENNAMETAL 4150257 is a screw machine length (stub-length) drill bit designed for high-performance drilling in metalworking and machining applications. Built from solid carbide with a multilayer TiAlN coating at the tip, this bit delivers hardness and heat resistance needed for demanding production environments. It measures 3.5039 inches in overall length with a 21/64 inch (0.3281 inch) cutting diameter, a 140-degree split-point angle for fast penetration and reduced walking, and a straight cylindrical shank at 0.3937 inch diameter. It is sized for use in CNC machining centers, drill presses, and screw machine setups where compact stub-length tools are required.

This drill bit is suited for precision hole-making in ferrous and non-ferrous metals, hardened alloys, and similar materials where tool life and dimensional accuracy are priorities. Its stub-length geometry provides greater rigidity than jobber-length bits, reducing deflection in tight-tolerance applications. The 3xD flute-to-diameter ratio and tapered web configuration support efficient chip evacuation in short-depth holes. Machinists, tool-and-die workers, and production shop technicians are the primary users. It conforms to DIN 6537K specifications.

Key Features

• Solid carbide construction for extended tool life in hard and abrasive materials
• Multilayer TiAlN tip coating increases heat and wear resistance at the cutting edge
• 140-degree point angle reduces thrust force and minimizes drill walking on entry
• Stub-length (screw machine length) body provides enhanced rigidity and reduced deflection
• Straight cylindrical shank at 0.3937 inch diameter fits standard collets and chucks
• Tapered web and regular spiral flute promote consistent chip evacuation

Compatibility

Designed as a stub-length carbide drill bit in the KENNAMETAL B041A-CPG series, conforming to DIN 6537K. Fits standard straight-shank tool holders and collet chucks accepting a 0.3937 inch shank diameter.

Installation Notes

Installation and tool changes should be performed by a qualified machinist with the machine powered down and locked out per applicable safety procedures. Ensure the shank is fully seated and properly torqued in the collet or chuck before operation. Carbide tooling is brittle and should not be subjected to impact or side-loading beyond designed parameters. Verify spindle speed and feed rate settings are appropriate for the workpiece material before engaging the cut.