Kennametal 4151638 Screw Machine Drill Bit 1.70mm Carbide

Product Description

The KENNAMETAL 4151638 is a screw machine length (stub) drill bit designed for precision drilling in metalworking and machining applications. Built from solid carbide and coated with TiAlN (TiN tip) for heat and wear resistance, this bit handles demanding materials encountered in production environments. It measures 1.70 mm in diameter with an overall length of 58.00 mm (2.2835 inches) and features a 140-degree split point for accurate self-starting entry and reduced thrust. The straight-cylindrical shank measures 4.00 mm in diameter, and the maximum drilling depth is 6.00 mm. It is manufactured to DIN 6537K specification.

This drill bit is suited for use in CNC machining centers, drill presses, and screw machine operations where tight tolerances and short flute geometry are required. The stub length provides added rigidity, making it appropriate for high-speed production drilling in steel, stainless steel, cast iron, and similar ferrous and non-ferrous materials. It is typically used by machinists, tool-and-die technicians, and CNC operators in job shop and production manufacturing settings. The 3xD flute-to-diameter ratio and tapered web configuration support chip evacuation in short-hole drilling cycles.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard materials
• TiAlN multilayer coating with TiN tip for elevated heat resistance and extended tool life
• 140-degree point angle for accurate entry and reduced walking on entry
• Stub (screw machine) length provides greater rigidity than jobber-length equivalents
• Straight-cylindrical shank at 4.00 mm diameter for standard collet or chuck mounting
• Manufactured to DIN 6537K specification for dimensional consistency
• Right-hand cutting with regular spiral flute for standard chip evacuation

Compatibility

Designed as a DIN 6537K-compliant stub drill bit in the KENNAMETAL B041A-CPG series, compatible with any spindle or chuck system accepting a 4.00 mm straight-cylindrical shank.

Installation Notes

Installation and use should be performed by qualified machinists or CNC technicians familiar with carbide tooling. Ensure the spindle or collet chuck is clean and properly torqued before seating the shank to prevent runout, which can fracture carbide at small diameters. Coolant-through is not supported on this bit; external coolant or cutting fluid is recommended to manage heat. Avoid hand-feeding against carbide tooling — use controlled feed rates appropriate for the workpiece material and machine rigidity.