Bi-Metal Hole Saw - Variable Pitch M3 HSS Multi-Material Cutter

Bi-Metal Hole Saw - Variable Pitch M3 HSS Multi-Material Cutter

The Bi-Metal Hole Saw is an M3 grade HSS multi-material hole saw designed for professional cutting through softwood, plywood, MDF, plasterboard, plastic, non-ferrous metals, and thin sheet metal. The variable pitch tooth pattern is the key performance differentiator: alternating tooth spacing reduces vibration during cutting, improves chip clearance from the kerf, and delivers a cleaner hole edge across a wider range of materials than a fixed-pitch saw. For electricians, plumbers, joiners, and general construction trades who cut through multiple materials on the same job, this is a working tool built around the demands of multi-trade site use. The diameter is stamped directly onto the saw body, which eliminates the identification errors that cost time on site when multiple sizes are in use simultaneously.

Why Choose the Bi-Metal Hole Saw

• M3 HSS cutting edge: higher vanadium content than M2 HSS delivers longer tooth life and better heat resistance on multi-material cutting.

• Variable pitch tooth pattern: alternating tooth spacing reduces vibration, improves chip clearance, and extends tooth life across all specified materials.

• Bi-metal construction: flexible spring steel body resists torsional stress whilst the HSS tooth tips maintain cutting aggression across the full material range.

• Diameter stamped on body: instant size identification on site where multiple sizes are in use simultaneously.

• 5/8 inch x 18 TPI thread mount: fits arbors without adaptors, covering the most common drill configurations on UK sites.

• Available from 14mm upwards: covers the full spread of hole sizes for electrical, plumbing, and joinery installations.

What's Included

• One Bi-Metal Hole Saw in the selected diameter size

 Specifications

Compatibility

Who Is This For?

The Bi-Metal Hole Saw is aimed at electricians, plumbers, heating engineers, joiners, drylining contractors, and general construction trades who regularly cut holes through multiple materials on the same job. It suits the electrician cutting cable entry points through plasterboard, timber stud walls, and plastic conduit trunking, the plumber cutting pipe penetrations through MDF, plywood, and thin sheet metal panels, and the joiner cutting access holes through softwood, plywood, and man-made boards for mechanical and electrical installations. This is a professional multi-material tool for sustained site use across a range of substrates, not a single-material specialist saw.

Typical Applications

• Cutting cable entry holes through plasterboard partitions and timber stud walls on electrical first and second fix

• Cutting pipe penetrations through softwood joists, plywood decking, and MDF panels during plumbing and heating installations

• Cutting access holes through plastic trunking, conduit boxes, and electrical enclosures

• Cutting ventilation and extract fan apertures through plasterboard ceilings and walls

• Cutting downlight apertures through plasterboard and MDF ceiling boards

• Cutting non-ferrous metal sheet for HVAC and ductwork penetrations and access panels

• Cutting thin sheet metal panels for cable management and electrical distribution installations

How to Use

1. Fit the hole saw onto a compatible arbor and confirm the pilot drill is correctly seated.

2. Mark the centre point on the workpiece before starting.

3. Set drill speed to suit the material: lower for non-ferrous metals, higher for plasterboard and softwood.

4. Allow the pilot drill to penetrate fully before the saw teeth contact the surface.

5. Apply steady forward pressure without forcing the cut.

6. Withdraw the saw periodically to clear swarf and sawdust from the tooth gullets.

7. Apply cutting lubricant when working on non-ferrous metals.

8. After breakthrough, reverse the drill briefly to loosen the plug.

9. Eject the plug through the slot apertures using a flat blade.

Safety

• Eye protection to EN 166 and cut-resistant gloves to EN 388 are mandatory.

• Secure the workpiece firmly before cutting to control breakthrough torque.

• Always locate concealed services before cutting through walls, floors, or ceilings.

• Never exceed the recommended drill speed for the selected material and diameter.

• Use the drill's auxiliary handle where available to manage breakthrough torque.

Maintenance

• Clean debris from the teeth after every use before storing.

• Apply a light coat of machine oil to the teeth before storage.

• Inspect teeth for chipping or wear before each use.

• Replace the saw when cutting performance deteriorates.

• Do not attempt on-site resharpening of worn teeth.

Frequently Asked Questions

Q: What is the difference between M3 and M2 HSS grade?

A: M3 has a higher vanadium content than M2, giving it greater hardness and wear resistance at high temperatures. In practice this means longer tooth life on multi-material cutting, reducing replacement frequency on busy sites.

Q: What does variable pitch mean and why does it matter?

 A: Variable pitch alternates the spacing between teeth to disrupt resonant vibration. This reduces operator fatigue, improves chip clearance, and extends tooth life across the full range of materials the saw cuts.

Q: What arbor do I need?

 A: The saw has a 5/8 inch x 18 TPI thread mount. Confirm your drill's arbor type before ordering.

Q: Can this saw cut stainless or hardened steel?

 A: No. Use a cobalt HSS or carbide-tipped hole saw for ferrous and hardened steel. Using this saw on those materials will damage the teeth rapidly.

Q: What drill speed should I use?

A: Lower speeds for non-ferrous metals and dense plastics, higher speeds for plasterboard and softwood. Larger diameters always require lower speeds than smaller ones on the same material.

Q: How do I remove a stuck plug?

A: Insert a flat blade through the slot apertures in the saw body and lever the plug out. Reversing the drill briefly before removal often loosens it enough to slide out cleanly.

Q: How do I extend tooth life on metal cutting?

 A: Use cutting lubricant, reduce drill speed, withdraw frequently to clear swarf, and clean and oil the saw after every metal cutting session.

Q: Why should I order from CMT Group?

 A: CMT Group has supplied UK construction sites since 2010 with next working day delivery, a FORS Silver accredited fleet covering 90% of the mainland, and the EDGE portal for agreed contract pricing and live delivery tracking.