Hertel 28681401 Screw Machine Drill Bit 27/64 in Carbide

Product Description

The HERTEL 28681401 is a screw machine length drill bit designed for high-performance drilling in tough ferrous and exotic materials. Built from solid carbide grade C2 and coated with titanium nitride (TiN), it delivers extended tool life and reduced cutting friction compared to standard high-speed steel bits. The 135-degree split point promotes fast penetration and minimizes walking on entry, eliminating the need for a center punch on most surfaces. At 3-3/8 inches overall length with a 2-inch flute length, the screw machine format provides added rigidity over jobber-length bits, making it well suited for short-hole drilling and CNC applications. This bit is installed and used by machinists, tool-and-die professionals, and maintenance technicians.

The 28681401 is engineered for drilling cast iron, nickel alloy, stainless steel, titanium alloy, and tool steel. The slow spiral flute geometry and web-thinned, parallel web configuration are specifically matched to these hard and work-hardening materials, promoting chip evacuation and reducing heat buildup at the cutting zone. The straight-cylindrical shank seats directly into standard drill chucks and collet holders without adapters, fitting manual drill presses, CNC machining centers, and turret lathes. The 0.4219-inch diameter with a close tolerance of plus 0.0000 to minus 0.0005 inches ensures accurate hole sizing in precision work.

Key Features

• Solid carbide C2 grade construction for hardness and wear resistance in ferrous and exotic alloys
• Titanium nitride (TiN) coating reduces friction and extends cutting life
• 135-degree split point for fast engagement and reduced thrust force
• Slow spiral flute geometry optimized for chip control in hard, work-hardening materials
• Web-thinned parallel web reduces cutting resistance and heat at the drill tip
• Close diameter tolerance of plus 0.0000 to minus 0.0005 inches for precision hole quality

Compatibility

Designed as a screw machine length replacement drill bit for use in standard drill chucks and collet holders accepting a straight-cylindrical shank. Primary workpiece materials include cast iron, nickel alloy, stainless steel, titanium alloy, and tool steel.

Installation Notes

Install into a compatible drill chuck or collet holder, ensuring the shank is fully seated and the chuck is tightened to the appropriate torque for the holder type. Secure the workpiece firmly before drilling to prevent movement. Confirm spindle speed and feed rate are appropriate for the workpiece material and bit diameter before engaging the cut. Coolant-through is not supported on this bit, so external cutting fluid or mist cooling is recommended when drilling stainless steel, titanium alloy, or other heat-sensitive materials.