Hertel 74130311 Screw Machine Drill Bit 5/16 in Cobalt

Product Description

The HERTEL 74130311 is a screw machine length drill bit designed for high-production drilling in metal and other hard materials. Built from cobalt high-speed steel (HSCO), it delivers superior heat resistance and edge retention compared to standard HSS tooling. The 135-degree split point reduces walking at entry and lowers the thrust required to start a hole, making it well-suited for hand-held drilling or drill press work on harder substrates. At 5/16 inch (0.3125 inch) diameter with a 2-13/16 inch overall length, this stub-length bit offers added rigidity and reduced deflection versus jobber-length alternatives. A licensed tool-and-die tech, machinist, or experienced maintenance professional would be the typical end user.

This bit is suited for drilling ferrous metals, stainless steel, cast iron, and other tough materials where standard HSS bits wear prematurely. The screw machine (stub) length format is common in CNC machining centers, turret lathes, bench drill presses, and hand drills where short overhang improves straightness. The 1-5/8 inch flute length accommodates typical material thickness in sheet metal and plate work. The parallel web configuration with web thinning reduces cutting resistance through the center of the bit.

Key Features

• Cobalt HSCO construction for extended tool life in hard and abrasive materials
• 135-degree split point reduces entry walking and lowers feed pressure
• Web-thinned parallel web reduces center cutting resistance
• Screw machine (stub) length at 2-13/16 inches OAL for increased rigidity and reduced deflection
• Right-hand cut with regular spiral flute for standard chip evacuation
• Straight cylindrical shank fits standard drill chucks without adapters

Compatibility

Designed as an OEM-style replacement or direct-use tooling for any standard drill chuck accepting a straight shank bit in the 0.3000 to 0.3500 inch diameter range.

Installation Notes

Installation is performed by machinists or maintenance technicians using a keyed or keyless drill chuck on a bench press, CNC machine, or hand drill. Secure the straight shank fully into the chuck before applying power. Use appropriate cutting fluid or coolant when drilling ferrous metals to preserve edge life, noting that this bit does not support coolant-through operation. Inspect the cutting edges for wear before each use and replace the bit if chipping or heat discoloration is observed at the point.