Hole saw Irwin 10504182 bi-metal 46 mm, variable teeth 4.5/5.5 TPI

Irwin 10504182 is a 46 mm bi-metal hole saw with a variable tooth pitch (4.5/5.5 TPI) engineered for cutting through a variety of common workshop materials. The bi-metal construction combines high-speed steel cutting edges with a flexible backing to resist wear and heat buildup during prolonged cutting. The variable tooth pitch improves chip evacuation and reduces vibration for more consistent hole quality when working with metal, wood and plastics.

Advantages

The bi-metal design provides enhanced durability and heat resistance compared with simple carbon-steel saws, extending tool life when cutting metal or mixed materials. Variable teeth (4.5/5.5 TPI) balance fast cutting action and smoother finishes, while reducing the risk of tooth clogging. The 46 mm diameter is a common size for plumbing, electrical and carpentry openings, and the saw’s geometry supports efficient chip removal and reduced binding.

Suitable for

• Cutting circular holes in thin to medium-thickness metal sheets (steel, aluminium)
• Making holes in wood and plywood for fittings and cable passages
• Drilling through plastics and composite panels
• Plumbing, electrical and general carpentry installation work

Key specifications

• Cutting diameter: 46 mm
• Tooth pitch: variable 4.5 / 5.5 TPI for combined fast cutting and smoother finish
• Material: bi-metal construction (high-speed steel teeth bonded to flexible backing)
• Intended materials: metal, wood, plastics
• Typical applications: through-holes for pipes, cables and fittings

How to use

Secure the hole saw to a compatible arbor and ensure the pilot drill bit is correctly seated. Mark the hole position and clamp the workpiece to prevent movement. Start drilling at low speed to establish the pilot hole, then increase speed appropriate to the material while applying steady, moderate pressure. For metal cutting, use cutting fluid to reduce heat and improve cutting life. Withdraw periodically to clear chips and prevent clogging.

Usage recommendations

Use slower speeds and cutting lubricant when drilling ferrous metals; for wood and plastics, higher speeds give faster progress. Always wear appropriate eye and hand protection and ensure the workpiece is securely clamped. Replace the hole saw if teeth are damaged or performance drops to maintain clean, accurate holes.