Hertel 16691339 Straight-flute Carbide Drill Bit 0.3937 in

Product Description

The HERTEL 16691339 is a straight-flute carbide drill bit designed for precision drilling in hard and difficult-to-machine materials. Built to Series 470 specifications, it features a 140-degree notched point with web thinning for improved chip evacuation and reduced thrust at entry. The cutting geometry is optimized for right-hand rotation and delivers tight diameter tolerance of +0.0000 to -0.0005 inches, making it suitable for applications where hole accuracy is critical. The bright, uncoated carbide construction uses C2 material grade, providing hardness and heat resistance without the variability of a coating. Licensed machinists, tool-and-die workers, and maintenance technicians are the typical end users.

This drill bit is rated for use in chrome alloy, heat-treated alloy, nickel alloy, stainless steel, carbon steel, and titanium alloy workpieces. It is well-suited for production and maintenance drilling in aerospace, industrial, and heavy fabrication environments where hard materials demand a rigid, non-flex flute design. The straight-flute geometry is particularly effective in materials prone to work hardening, such as stainless and nickel alloys, where standard spiral flutes may chatter or deflect.

Key Features

• Straight-flute design resists deflection in hard and work-hardening alloys
• 140-degree notched point reduces entry thrust and improves centering
• Web-thinned geometry promotes chip clearance and lowers cutting force
• C2 carbide grade provides hardness and thermal stability without a coating
• Diameter tolerance of +0.0000 to -0.0005 inches supports close-tolerance hole requirements
• Two-flute configuration standard for straight-flute carbide drilling applications

Compatibility

Designed for use in chrome alloy, heat-treated alloy, nickel alloy, stainless steel, steel, and titanium alloy workpieces as a primary and secondary material application per Series 470 specifications.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with carbide tooling handling and machine setup. Secure the bit properly in a compatible chuck or collet rated for the shank diameter before operating. Do not exceed the recommended drilling depth of 3.25 inches as indicated by the overall length specification. Carbide tooling is brittle — avoid side-loading, interrupted cuts without proper feed rate adjustment, or dropping the bit on hard surfaces.