Kennametal 4121529 Screw Machine Drill Bit 4.00 Mm

Product Description

The KENNAMETAL 4121529 is a solid carbide screw machine length drill bit designed for high-performance drilling in demanding materials. It features a 4.00 mm diameter, a 140-degree split point, and a titanium nitride (TiN) tip coating to extend tool life and reduce built-up edge. The overall length is 66.00 mm (2.598 inches), with a 6.00 mm straight cylindrical shank. Two regular spiral flutes provide efficient chip evacuation, and the tapered web configuration adds rigidity at the cutting edge. Coolant-through capability supports deep-hole drilling in difficult alloys. Licensed machinists and tool-and-die professionals are the primary installers of this bit.

This drill bit is suited for drilling stainless steel, cast iron, and high-temperature alloys in screw machine and production machining environments. The short overall length and stiff geometry reduce deflection and improve hole accuracy in CNC lathes, screw machines, and machining centers. The flute-to-diameter ratio of 3xD limits the maximum drilling depth to 17.00 mm (0.669 inches), making it appropriate for shallow to mid-depth holes in hard, abrasive materials. The B051A series follows DIN 6537K geometry standards, supporting consistent tool replacement across mixed fleets.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard and abrasive workpiece materials
• TiN tip coating reduces friction and extends cutting life in stainless steel and cast iron
• 140-degree point angle improves self-centering and reduces thrust in tough alloys
• Coolant-through design supports chip flushing and heat control at depth
• Tapered web configuration adds core strength and reduces chatter
• DIN 6537K geometry for dimensional consistency and drop-in replaceability

Compatibility

Designed for use in CNC screw machines, lathes, and machining centers where a 6.00 mm straight shank is accepted. Primary workpiece materials include stainless steel, cast iron, and high-temperature alloys. Conforms to DIN 6535 and DIN 6537 standards. Fits the B051A series drill family.

Installation Notes

Install and remove drill bits only after the spindle has come to a complete stop and machine power is locked out per established LOTO procedures. Verify that the tool holder collet or chuck accepts a 6.00 mm straight shank before seating the bit. Do not exceed the rated maximum drilling depth of 17.00 mm to avoid flute overload and potential bit breakage. Coolant supply should be confirmed active before initiating a cut in stainless steel or high-temperature alloys.