Kennametal 4150191 Screw Machine Drill Bit 3.90mm Carbide

Product Description

The KENNAMETAL 4150191 is a screw machine length (stub) drill bit designed for high-precision drilling in metal and hard materials. Built from solid carbide with a multilayer TiAlN coating at the tip, this bit delivers extended tool life and thermal resistance in demanding production environments. It features a 140-degree point angle for aggressive, self-centering entry with reduced thrust. The straight-cylindrical shank measures 6.00 mm in diameter, and the overall length is 66.00 mm (approximately 2.60 inches). With a right-hand, regular spiral flute design and tapered web configuration, it suits CNC machining centers, drill presses, and screw machine applications where rigidity and repeatability are critical.

This drill bit is intended for use in metalworking and precision machining environments, including production shops, job shops, and toolrooms. The stub-length body reduces deflection and improves rigidity compared to jobber-length equivalents, making it well suited for close-tolerance hole work in steel, stainless, cast iron, and similar ferrous materials. It is typically installed in machining centers, CNC lathes, or drill presses where accurate, repeatable hole diameter is required. The 3xD flute-to-diameter ratio supports chip evacuation in shallow to moderate-depth holes without coolant-through assist.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard materials
• Multilayer TiAlN coating at tip reduces heat buildup and extends cutting life
• 140-degree point angle for fast, self-centering penetration with lower thrust
• Stub (screw machine) length body minimizes deflection for tight-tolerance work
• Right-hand regular spiral flute with tapered web for efficient chip clearing
• Straight-cylindrical shank compatible with standard collets and drill chucks
• Conforms to DIN 6537K specification for dimensional consistency

Compatibility

Designed as an OEM-style replacement and standard production drill bit in the KENNAMETAL Series B041A-CPG. Fits any toolholder or collet accepting a 6.00 mm straight-cylindrical shank. Suitable for the decimal-inch diameter range 0.1500 to 0.2000 inch and metric range 3.50 to 5.00 mm.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician. Ensure the machine spindle is fully powered down and locked out before changing tooling. Secure the shank fully in the collet or drill chuck to the minimum grip depth recommended for the holder being used; insufficient engagement increases deflection and risk of pullout. Do not exceed the maximum drilling depth of 17.00 mm (approximately 0.67 inches) for this stub-length geometry without retracting to clear chips.