Disston Company 504688 Hss Black Oxide Drill Bit 5/16 X 12 in

Product Description

The DISSTON COMPANY 504688 is a 5/16-inch by 12-inch extra-length high speed steel drill bit finished with a black oxide coating. Designed for trade and industrial use, it features a 135-degree split-point tip with four cutting edges that self-center on contact, reducing walking and enabling fast penetration without a center punch. The black oxide tempering treatment lowers frictional heat and improves chip evacuation during drilling. The extra 12-inch length makes this bit well suited for deep-bore applications in framing, mechanical, and light fabrication work where a standard-length bit cannot reach.

This drill bit is recommended for use in wood, plastic, wallboard, plywood, soft metals, aluminum, brass, and bronze. It is rated for occasional use in stainless steel and other hard metals. The extra-length profile is particularly useful for electricians drilling through deep wall cavities, plumbers boring through floor assemblies, and HVAC technicians running conduit or tubing through structural members. Each unit is sold individually and packaged on a card for single-piece storage and dispensing.

Key Features

• 135-degree split-point tip with four cutting edges eliminates walking and reduces the need for a pilot hole
• Extra-length 12-inch body reaches deep cavities and through-wall applications inaccessible to standard bits
• High speed steel construction provides hardness and heat resistance during sustained drilling
• Black oxide tempering treatment reduces frictional resistance and improves chip flow out of the bore
• Rated for wood, plastic, wallboard, plywood, aluminum, brass, and bronze with occasional use in stainless steel and hard metals

Compatibility

Designed as a standard-shank extra-length drill bit compatible with 3/8-inch and 1/2-inch keyed or keyless drill chucks commonly used in corded and cordless power drills.

Installation Notes

Installation should be performed by a qualified tradesperson familiar with drilling procedures appropriate to the material being worked. Secure the workpiece before drilling and confirm the chuck is fully tightened on the shank before operation. When drilling metal, use appropriate cutting fluid to extend bit life and manage heat. Wear eye protection at all times during use.