Kennametal 4151284 Drill Bit 21/32 Inch Solid Carbide

Product Description

The KENNAMETAL 4151284 is a screw machine length (stub) solid carbide drill bit designed for high-performance drilling in demanding metalworking and machining applications. Built to DIN 6537K standards, it features a 21/32 inch (0.6562 inch) diameter, a 140-degree split point for accurate self-starting entry, and a multilayer TiAlN coating at the tip to extend tool life under heat and abrasion. The overall length is 4.8425 inches (123.00 mm), and the straight cylindrical shank measures 0.7087 inches (18.00 mm) in diameter. Coolant-through capability supports chip evacuation and thermal management during deep-hole operations. This bit is intended for installation and use by machinists, tool-and-die professionals, and CNC operators.

This drill bit fits production drilling environments where stub-length rigidity reduces deflection and improves hole quality. Its 3xD flute-to-diameter ratio and regular spiral flute geometry make it well suited for drilling steel, stainless steel, cast iron, and similar ferrous materials. The maximum drilling depth is 2.0079 inches (51.00 mm), and the flute length is 2.8740 inches (73.00 mm). It is commonly used in CNC machining centers, drill presses, and screw machine setups where consistent diameter tolerance and concentricity are required. The right-hand cutting direction is standard for conventional spindle rotation.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard and abrasive materials
• 140-degree point angle for accurate entry and reduced thrust force
• TiAlN tip coating extends tool life under elevated cutting temperatures
• Coolant-through design supports chip flushing and heat management in deep-hole drilling
• Stub (screw machine) length reduces deflection and improves hole straightness
• DIN 6537K specification ensures dimensional consistency and interchangeability
• Tapered web configuration maintains core strength while improving chip flow

Compatibility

Designed as an OEM-style replacement or direct-use solid carbide stub drill conforming to DIN 6537K, suitable for use in standard straight-shank drill chucks and collet holders accepting a 0.7087-inch shank diameter.

Installation Notes

Installation and use should be performed by qualified machinists or CNC technicians familiar with carbide tooling. Ensure the machine spindle is fully stopped and locked out before changing tooling. Secure the straight shank in a properly sized collet or drill chuck to the chuck manufacturer's recommended torque; carbide tooling is brittle and susceptible to breakage if improperly clamped or side-loaded. Verify coolant-through lines are clear and pressurized to the machine's specified operating range before running the spindle.