Hertel 74131285 Screw Machine Drill Bit Letter Q Cobalt

Product Description

The HERTEL 74131285 is a screw machine length cobalt drill bit sized to Letter Q (0.3320 inches decimal) with a 135-degree split point and web-thinned geometry. Screw machine length bits are shorter than jobber-length bits, which increases rigidity and reduces deflection in production drilling, CNC, and lathe work. The cobalt steel construction handles elevated heat generated when drilling hardened steels, stainless, cast iron, and other tough alloys. The split point starts on contact without a center punch, and the web-thinned tip reduces thrust and improves chip evacuation. Two regular spiral flutes move chips out of the hole efficiently. Finish is straw, indicating a heat-treated cobalt blank with no additional coating applied.

This bit is suited to production shops, machine shops, and maintenance facilities where short, rigid tooling is preferred over standard jobber-length drills. Typical applications include drilling into structural steel, stainless steel fastener holes, alloy steel components, and hard ferrous materials where high-speed steel bits lose their edge prematurely. The straight cylindrical shank seats in standard drill chucks, collets, and quick-change holders without modification. Right-hand cutting direction is the standard for conventional drill press, CNC mill, and lathe tailstock use.

Key Features

• Letter Q size - 0.3320 inches decimal, within the 0.3000 to 0.3500 inch range series
• 135-degree split point starts on contact, eliminating center-punch requirements and reducing walking
• Web-thinned, parallel web configuration lowers thrust load and improves chip flow
• Cobalt steel construction resists heat buildup when drilling hard and abrasive alloys
• Screw machine (stub) length at 3.0 inches OAL increases rigidity and reduces deflection vs. jobber-length bits
• Straight cylindrical shank fits standard chucks and collets without adapters
• No coolant-through feature - designed for external coolant or dry cutting as appropriate to application

Compatibility

Designed as a standard straight-shank screw machine length drill bit compatible with any drill press, CNC machining center, turret lathe tailstock, or hand drill chuck accepting a straight cylindrical shank in the appropriate size range.

Installation Notes

Installation and use should be performed by machinists or qualified trades personnel familiar with metal cutting operations. Secure the shank fully in the chuck or collet and verify concentricity before running at speed. Power down and de-energize the machine before changing tooling. Use appropriate cutting fluid or coolant for the work material when drilling stainless or hardened alloys to extend tool life and maintain safe operating temperatures.