Hertel 74131830 Cobalt Drill Bit Letter J 135 Degree

Product Description

The HERTEL 74131830 is a cobalt screw machine length drill bit designed for high-performance drilling in tough materials. Built to the HSCO135-TA series standard, it features a 135-degree split point that reduces walking and allows the bit to self-center without a pilot hole. The TiAlN coating increases surface hardness and heat resistance, extending tool life in abrasive or high-speed applications. At 2-11/16 inches overall length with a 1-1/2 inch flute length, this is a stub-length format engineered for rigidity and reduced deflection. Licensed machinists, tool-and-die technicians, and maintenance trades install this bit in drill presses, CNC machines, and hand-held power tools.

This drill bit is sized at Letter J, which corresponds to 0.2770 inch decimal equivalent. It is suited for production drilling in steel, stainless steel, cast iron, and other hard or work-hardening metals where standard high-speed steel bits wear prematurely. The screw machine length format is common in manufacturing, fabrication, and maintenance environments where shorter bit length improves stability in confined or tight-clearance drilling setups. The straight shank fits standard drill chucks without adapters.

Key Features

• Letter J size, 0.2770 inch decimal equivalent, within the 0.2500 to 0.3000 inch size range
• 135-degree split point reduces thrust force and eliminates center-punch requirements
• TiAlN coating provides heat and wear resistance for extended tool life in hard materials
• Cobalt tool material maintains hardness at elevated cutting temperatures
• Web-thinned parallel web reduces cutting resistance and improves chip evacuation
• Right-hand, regular spiral flute with straight cylindrical shank for standard chuck compatibility

Compatibility

Designed as a screw machine length replacement or production drill bit compatible with standard straight-shank drill chucks on drill presses, CNC drilling machines, and handheld power tools accepting bits in the 0.2500 to 0.3000 inch diameter range.

Installation Notes

Installation is performed by machinists or maintenance technicians using a standard keyed or keyless drill chuck. Ensure the chuck and spindle are clean and the shank is fully seated before tightening. Power down and de-energize the machine before changing tooling. Follow machine manufacturer speed and feed recommendations for cobalt bits when drilling hardened or stainless materials to avoid premature coating wear.