Hole Saw M.K. Morse Advanced Bi-Metal 21 mm (13/16") — bi-metal hole saw, M.K. Morse

The M.K. Morse Advanced Bi-Metal 21 mm (13/16") hole saw is a precision cutting tool designed for making clean, round holes with a diameter of 21 mm. Constructed from bi-metal materials, this hole saw combines a high-speed steel cutting edge with a flexible alloy body to deliver improved durability and longer cutting life compared with standard carbon-steel hole saws. It is intended for use with hand drills and drill presses in tasks that require accurate, repeatable holes in thin to moderate thickness metals and a variety of other materials.

Advantages

The bi-metal construction provides a balance of hardness and toughness, increasing resistance to dulling and chipping during metal cutting. The 21 mm diameter gives precise hole sizing for fittings and fasteners commonly used in plumbing, electrical and HVAC installations. The advanced tooth geometry is optimized for faster cutting and reduced vibration, while compatibility with standard pilot drills and arbors allows quick setup and swap between jobs.

Suitable for

• Coring holes in sheet metal for conduit, pipes and cable glands
• Creating access and mounting holes in electrical boxes and panels
• HVAC installations where consistent 21 mm openings are required
• General maintenance and repair work requiring precise small-diameter holes

Key specifications

• Cutting diameter: 21 mm (13/16")
• Material: bi-metal construction with high-speed steel cutting edge
• Intended use: metal and mixed-material cutting in thin to moderate thicknesses
• Compatible with: standard drill chucks, arbors and pilot drills for hole saws
• Typical applications: plumbing, electrical, HVAC, maintenance and general fabrication

How to use

Secure an appropriate arbor and pilot drill in your drill or drill press and attach the 21 mm M.K. Morse bi-metal hole saw. Mark the center point of the hole on the workpiece, align the pilot bit and start drilling at a low speed to establish the cut. Apply steady pressure and maintain consistent feed; increase speed gradually as the hole saw cuts into the material. Periodically withdraw to clear chips and allow cooling, especially when cutting metal. After cutting, remove any burrs from the hole edges with a file or deburring tool.

Usage recommendations

For best results when cutting metal, use cutting fluid or lubricant to reduce heat and extend blade life. Use appropriate personal protective equipment such as safety glasses and gloves. Match drill speed and feed to the material thickness: lower speeds for harder metals and thicker workpieces, higher speeds for softer materials. Inspect the hole saw teeth before each use and replace the tool if teeth are damaged or excessively worn.