Hertel 83238931 Screw Machine Drill Bit Letter X Hss

Product Description

The HERTEL 83238931 is a screw machine length drill bit sized to Letter X (0.3970 inches), designed for high-speed steel cutting applications in metal fabrication, machining, and general manufacturing environments. The 135-degree split point reduces walking at startup and requires less feed pressure than a standard 118-degree point. An oxide coating provides corrosion resistance and moderate lubricity. At 3-5/16 inches overall length, this short-series bit fits tight-clearance fixtures and turret setups where a jobber-length bit would not clear. Licensed machinists, tool-and-die technicians, and production drill press operators are the primary users of this type.

This bit is suited for screw machine work, CNC turret drilling, drill press operations, and short-reach hand-drill applications where rigidity is more important than reach. The straight-cylindrical shank at 0.3970 inches diameter seats directly in standard drill chucks and collet systems. Its heavy-duty grade and web-thinned, parallel-web configuration make it appropriate for production drilling in ferrous and non-ferrous metals. It falls within the 0.3500 to 0.4000 inch decimal inch size range and meets NAS 907 specification requirements.

Key Features

• Letter X size — 0.3970 inches decimal equivalent for precise sizing
• 135-degree split point reduces thrust and self-centers on contact
• Web-thinned parallel web lowers cutting resistance in metal stock
• Oxide-coated high-speed steel resists corrosion and light heat buildup
• Screw machine (short-series) length improves rigidity in tight setups
• Meets NAS 907 specification for heavy-duty drill bit grade

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit for standard drill chucks and collet holders accepting a 0.3970-inch straight-cylindrical shank. Suitable for use in drill presses, CNC turrets, and hand-held drilling equipment within the 0.3500 to 0.4000 inch size range category.

Installation Notes

Install and remove drill bits only when the machine is fully de-energized and the chuck or collet is stationary. Ensure the shank is fully seated and the chuck is tightened before initiating a cut. Use appropriate cutting fluid for ferrous materials to extend bit life and maintain dimensional accuracy. Inspect the split point for chipping or wear before each use; a damaged point will affect hole quality and can break under feed pressure.