Disston Company 287805 Cobalt Hss Drill Bit 17/64 in 135 Split Point

Product Description

The DISSTON COMPANY 287805 is a jobber-length, high speed steel drill bit with 8 percent cobalt content, designed for drilling into hard and abrasion-resistant metals. The 135-degree split point geometry features four cutting edges that allow fast penetration and eliminate bit walking on entry — no center punch required. Cobalt content raises the heat tolerance of the bit, maintaining cutting efficiency at temperatures in excess of 1,000 degrees Fahrenheit. The straight shank fits standard three-jaw drill chucks. At 17/64 inch diameter and 4.125 inches overall length, this bit suits a wide range of jobber-length drilling applications in the trades.

This bit is built for drilling in hard metals where standard high speed steel bits lose their edge quickly. Recommended materials include heat-treated steel, stainless steel, chrome alloy, manganese steel, titanium, and armor plate. It is a practical choice for HVAC technicians, pipefitters, electricians, and maintenance mechanics who regularly work with stainless fastener holes, sheet metal fabrication, or structural steel. The 135 split point reduces thrust required to start the hole, which is a real advantage when drilling without a drill press or fixed setup.

Key Features

• 135-degree split point with four cutting edges for fast starts and reduced walking
• 8 percent cobalt content for heat resistance beyond 1,000 degrees Fahrenheit
• High speed steel base material with cobalt for extended tool life in hard metals
• Jobber length at 17/64 inch diameter and 4.125 inches overall
• Straight shank fits standard drill chucks — no adapter needed
• Suitable for heat-treated steel, stainless steel, titanium, chrome, manganese steel, and armor plate

Compatibility

Designed for use with standard three-jaw drill chucks accepting straight-shank jobber-length bits. Recommended for drilling hard metals including heat-treated steel, stainless steel, chrome alloy, manganese steel, titanium, and armor plate.

Installation Notes

Drilling cobalt bits into hard metals generates significant heat — use cutting fluid or oil to extend bit life and improve hole quality. Secure the workpiece firmly before drilling to prevent movement. When drilling stainless steel or titanium, use steady moderate pressure and avoid letting the bit spin without cutting, as work hardening will dull the tip rapidly. Follow shop safety practices including eye protection whenever drilling metal.