Hertel 42030 Cobalt Jobber Drill Bit 31/64 in 135 Deg

Product Description

The HERTEL 42030 is a cobalt jobber-length drill bit designed for high-performance drilling in tough materials. Built from cobalt steel and finished with an oxide and gold coating, this bit handles heat and wear better than standard high-speed steel. The 135-degree split point starts on contact without walking, reducing the need for a center punch on most surfaces. At 5-7/8 inches overall length with a 4-3/8 inch flute length, it fits standard drill chucks and drill presses used daily in mechanical, HVAC, plumbing, and electrical trade work. The straight cylindrical shank and right-hand spiral flute make it compatible with virtually any benchtop or handheld drilling setup.

This bit is sized at 31/64 inch (0.4844 inch decimal equivalent), placing it in the 0.4000 to 0.5000 inch diameter range. It is suited for drilling ferrous metals, stainless steel, cast iron, and other hard materials commonly encountered during equipment installation, conduit work, pipe hangers, and structural mounting. The 2-flute regular spiral geometry clears chips efficiently in both through-hole and blind-hole applications. Trades including HVAC technicians, pipefitters, and electricians will find this bit useful for field drilling and fabrication tasks where standard HSS bits wear prematurely.

Key Features

• Cobalt steel construction for extended tool life in hard and abrasive materials
• Oxide and gold coating reduces friction and improves heat resistance
• 135-degree split point eliminates walking and reduces thrust required to start a hole
• Right-hand cut, 2-flute regular spiral design for efficient chip evacuation
• Straight cylindrical shank fits standard 3-jaw drill chucks without modification
• Flute-to-diameter ratio of 5xD provides rigidity while maintaining reach for most trade applications

Compatibility

Designed as a standard jobber-length drill bit with a straight cylindrical shank, compatible with handheld drills, drill presses, and magnetic base drills accepting bits in the 31/64 inch diameter range.

Installation Notes

Installed by machinists, HVAC technicians, electricians, plumbers, and general trade professionals using standard drill equipment. Secure the shank fully in the chuck and verify chuck key is removed before operation. Use cutting fluid or lubricant when drilling ferrous metals and stainless steel to extend bit life and maintain cut quality. Inspect the cutting edges before each use and replace the bit if chipping or excessive wear is present.