Hertel 4139697 Cobalt Jobber Drill Bit 9/32 Inch

Product Description

The HERTEL 4139697 is a cobalt jobber-length drill bit designed for high-performance holemaking in ferrous and hard metals. It features a 135-degree split point that reduces walking at contact and requires less thrust to start a hole. The TiAlN coating increases surface hardness and heat resistance, extending tool life in demanding cutting applications. With an overall length of 4.25 inches and a flute length of 2.9375 inches, this bit fits standard drill chucks and drill presses used in metalworking and fabrication environments. It is suited for machinists, tool-and-die trades, and general metal fabrication shops.

This drill bit is sized at 9/32 inch (0.2812 inch decimal) with a straight cylindrical shank of matching diameter. It is intended for use in ferrous metals, stainless steel, cast iron, and other hard materials where standard high-speed steel bits lose edge quickly. The regular spiral flute promotes chip evacuation during through-hole and blind-hole drilling. The web-thinned, tapered web geometry reduces cutting resistance and helps maintain accuracy at the point. Typical applications include production drilling, maintenance and repair operations, and precision metalwork on manual or CNC-equipped drill presses and mills.

Key Features

• Cobalt construction with Max Output grade rating for extended tool life in hard and abrasive materials
• TiAlN coating improves heat resistance and surface hardness during high-speed cutting
• 135-degree split point reduces thrust requirements and prevents bit walking at hole start
• Web-thinned, tapered web design lowers cutting resistance and maintains point integrity
• Regular spiral flute with right-hand cutting direction promotes consistent chip removal
• Straight cylindrical shank fits standard three-jaw chucks without adapters

Compatibility

Designed as a jobber-series drill bit for use in standard drill chucks accepting a 9/32 inch straight cylindrical shank, compatible with drill presses, hand drills, and CNC spindles configured for that shank diameter.

Installation Notes

Installation is performed by machinists or metal fabrication tradespeople. Secure the shank fully in the chuck and verify runout before cutting. Coolant-through capability is not supported on this bit, so apply cutting fluid externally when drilling hard or stainless alloys to manage heat buildup. Never force a dull bit — replace when point geometry shows visible wear to avoid workpiece damage or bit breakage.