Hertel 04138400 Cobalt Jobber Drill Bit 25/64 in

Product Description

The HERTEL 04138400 is a cobalt jobber-length drill bit designed for heavy-duty holemaking in ferrous and hard materials. It features a 135-degree split point that reduces walking on entry and lowers thrust requirements, making it well suited for production drilling and maintenance work. The oxide and TiN coating improves surface hardness and heat resistance. At 5.125 inches overall length with a 3.75-inch flute, this bit fits standard drill chucks and drill presses without modification. It is sized at 25/64 inches (0.3906 inches decimal), turns right-hand, and carries a straight-cylindrical shank.

This bit is intended for metal fabrication, mechanical contracting, and industrial maintenance applications where standard high-speed steel bits wear out prematurely. The cobalt construction handles stainless steel, hardened alloys, cast iron, and similar tough materials that generate high cutting temperatures. It is a single-piece, single-use retail unit with no coolant-through capability, making it appropriate for hand-held drill use as well as bench and floor drill press work. Machinists, pipefitters, millwrights, and general maintenance trades routinely specify cobalt jobber bits in this size range.

Key Features

• Cobalt construction rated for heavy-duty drilling in hardened and ferrous materials
• 135-degree split point reduces walking and lowers required thrust at entry
• Oxide and TiN dual coating improves heat resistance and surface hardness
• Web-thinned, tapered web configuration reduces cutting resistance through the full flute depth
• Straight-cylindrical shank fits standard 3-jaw chucks without an adapter
• Regular spiral flute with right-hand cutting direction for conventional drill rotation

Compatibility

Designed as an OEM-style replacement jobber drill bit for use in any standard drill press, magnetic drill, or hand-held drill accepting a straight-cylindrical shank in the 25/64-inch size range.

Installation Notes

This bit is installed and removed by a licensed machinist, pipefitter, or qualified maintenance technician using a standard keyed or keyless chuck. Secure the workpiece before drilling and ensure the drill press or hand tool is powered off and unplugged before changing bits. Use cutting fluid or lubricant when drilling stainless or hardened alloys to extend bit life. Dispose of worn bits per local sharps and metal-waste handling procedures.