Cleveland C70120 Cobalt Jobber Drill Bit 8.1 Mm

Product Description

The CLEVELAND C70120 is a cobalt jobber-length twist drill bit designed for demanding metal-removal applications in professional shop and field environments. Built to M42 cobalt steel material grade, this bit carries a gold oxide coating that aids in heat resistance and surface hardness. The split point geometry at 135 degrees reduces walking on entry and lowers thrust force compared to conventional 118-degree points. Right-hand spiral flutes in a regular helix evacuate chips efficiently, making this bit a reliable choice for machinists, maintenance technicians, and fabricators working with aluminum and other metals.

The C70120 fits standard jobber-length drill applications in machine shops, maintenance and repair operations, and light fabrication environments. Its 8.1 mm diameter and straight cylindrical shank seat directly into drill presses, hand drills, and CNC equipment using standard drill chucks. The gold oxide finish and M42 cobalt construction make it appropriate for high-production runs or intermittent use where tool longevity under heat and feed pressure matters. Primary workpiece material is aluminum, though cobalt-grade construction also handles steel and other ferrous alloys.

Key Features

• M42 cobalt steel construction delivers elevated hardness and heat resistance over standard HSS bits
• 135-degree split point reduces thrust and prevents bit walking on flat or curved workpiece surfaces
• Gold oxide coating improves surface hardness and reduces friction during cutting
• Web-thinned, tapered web design lowers cutting resistance and improves chip clearance
• Right-hand spiral flutes with regular helix provide consistent chip evacuation
• Meets NAS 907 Type J specification for dimensional and performance standards

Compatibility

Designed as an OEM-style jobber-length drill bit for use in standard drill chucks accepting a straight cylindrical shank; compatible with drill presses, hand drills, and CNC spindles sized for the 0.3189-inch shank diameter.

Installation Notes

Installation of this bit is performed by machinists, fabricators, and maintenance technicians using standard drill chucks or collet systems. Ensure the chuck or collet is fully tightened and the workpiece is secured before operation. Set spindle speed appropriate to the workpiece material and bit diameter per standard machining feeds-and-speeds references. Inspect the cutting edges for wear or chipping before each use and replace the bit if the split point or flute geometry is damaged.