Cleveland C70086 Cobalt Jobber Drill Bit 3.9 Mm

Product Description

The CLEVELAND C70086 is a cobalt jobber-length drill bit designed for heavy-duty drilling in metalworking and fabrication applications. Built from M42 cobalt high-speed steel and finished with a gold oxide coating, this bit delivers extended tool life when drilling hard and abrasive materials. It features a 135-degree split point that reduces walking and requires no center punch on most workpieces. The straight-cylindrical shank measures 0.1535 inches in diameter, and the overall length is 2.95 inches. With a regular spiral flute and web-thinned, tapered web configuration, it provides efficient chip evacuation and consistent cutting performance. Licensed tradespeople and machining professionals install this bit in standard drill chucks and drill presses.

The C70086 is suited for drilling aluminum and similar non-ferrous and light ferrous materials in residential, commercial, and industrial settings. At 3.9 mm (0.1535 inches) in diameter, it falls within the 3.00 to 4.00 mm size range and meets NAS 907 Type J standards. It is used in metal fabrication shops, HVAC sheet metal work, plumbing rough-in drilling, and electrical panel work where precise, small-diameter holes are required. The two-flute spiral design handles a wide range of drill press and handheld drill applications without coolant-through capability.

Key Features

• M42 cobalt high-speed steel construction rated for heavy-duty drilling applications
• Gold oxide coating extends surface hardness and reduces heat buildup during cutting
• 135-degree split point reduces thrust force and prevents bit walking without a center punch
• Web-thinned, tapered web design promotes efficient chip removal through two spiral flutes
• Straight-cylindrical shank fits standard drill chucks without adapters
• Meets NAS 907 Type J specification for consistent dimensional and performance standards

Compatibility

Designed as a heavy-duty jobber-length drill bit in Series 2213, the C70086 is compatible with standard drill chucks accepting a 0.1535-inch straight-cylindrical shank. Primary workpiece material is aluminum; the NAS 907 Type J rating indicates suitability across light metalworking applications within the 3.00 to 4.00 mm diameter range.

Installation Notes

Installation is performed by machinists, fabricators, or licensed tradespeople using a standard keyless or keyed drill chuck on a drill press or handheld power drill. Secure the shank fully in the chuck before operation and confirm the chuck key is removed prior to starting the drill. Do not exceed the recommended speed range for the workpiece material and bit diameter. Inspect the cutting edges for wear or chipping before each use and replace the bit if the point geometry is compromised.