What a Hole Saw Is
A hole saw is a cylindrical cutting attachment that cuts a wide, circular opening and leaves a core (or plug) rather than grinding the whole hole to dust. It is used in a drill or drill press and is common for door hardware, plumbing and electrical openings, and recessed lighting.
A hole saw setup usually has three parts:
- The saw (cup): the cylinder with teeth or an abrasive edge.
- The arbor (or mandrel): attaches the saw to the drill. The arbor has a shank that goes into the chuck. See drill shank and chuck types.
- The pilot bit: a twist bit in the middle that starts the hole and keeps the saw centred.
Hole Saw Types by Cutting Edge
Bi-Metal Hole Saws
Bi-metal saws have high-speed steel teeth on a flexible steel backing. They are the common general-purpose choice and cut wood, plastics, aluminium and thinner mild steel. Many have slots that help you pry out the core. Cobalt-enriched versions are sold for tougher metals.
Carbide-Tipped Hole Saws
These have carbide teeth, which stay sharp longer in demanding materials. They are used for hard or abrasive jobs such as stainless steel, thick metal, fibre cement or hardwoods, according to manufacturers. They cost more than bi-metal. Check the instructions for the materials the manufacturer approves.
Carbide Grit Hole Saws
Rather than teeth, a coating of carbide grit grinds the material. They can cut materials such as ceramic tile, brick, cast iron and fibreglass. They are typically used at slower speeds.
Diamond Hole Saws
A diamond-coated edge is made for very hard, brittle materials such as porcelain tile, glass and stone. Many are used with water to keep the edge cool and reduce dust. Follow the maker’s guidance on wet or dry use.
Tungsten Carbide Grit and Specialty Saws
Some specialty saws target materials like plaster or tile. Product names vary, so look at the listed materials rather than the name alone.
Adjustable and Other Hole Cutters
Adjustable hole cutters (sometimes called fly cutters or circle cutters) use a movable blade on an arm to cut variable sizes. They suit drill presses, not hand drills, and need great care because of the exposed blade. Some other cutters, such as Forstner or self-feeding bits, also make large holes in wood. See types of wood drill bits.
Quick Comparison
| Type | Typical materials | Notes |
|---|---|---|
| Bi-metal | Wood, plastic, aluminium, thin steel | General purpose, affordable |
| Carbide-tipped | Hard metals, abrasive materials | Durable, higher cost |
| Carbide grit | Tile, brick, cast iron | Grinds, slower |
| Diamond | Porcelain, glass, stone | Often used with water |
| Adjustable | Wood, sheet material | Drill press only |
How to Pick a Hole Saw
- Match the material. This matters more than anything else.
- Choose the diameter. Measure the fitting or pipe, and allow for any clearance needed. Common sizes run from under an inch to several inches.
- Check the depth. The saw’s depth should exceed the material thickness, or you may need to cut from both sides.
- Look at the arbor. Make sure it fits your drill and the saw’s thread size.
- Consider a kit only if you will use most of the sizes.
Tips for Using a Hole Saw
- Mark the centre and secure the workpiece.
- Start with the pilot bit, then let the saw engage.
- Use a slower speed, especially in metal. Hole saws with large diameters generally need lower speeds.
- Keep pressure steady, and clear chips by lifting the saw from time to time.
- Use cutting fluid when cutting metal, if recommended.
- Be ready for the saw to catch. Use a drill with a side handle, hold it firmly, and wear safety glasses. A drill press is a safer option for many jobs; see types of drill presses.
- Extract the core carefully. Hot cores can burn.
For other bit types for drills, see our drill bit types guide.
FAQ
What type of hole saw is best for wood?
A bi-metal hole saw is a common and sensible choice. Carbide-tipped saws can be used where wood contains nails or is abrasive, according to manufacturer guidance.
Which hole saw is best for metal?
Bi-metal for thin mild steel and aluminium, carbide-tipped or cobalt for tougher metals. Check the packaging.
Can I cut tile with a hole saw?
Yes, with a diamond or carbide grit hole saw designed for tile. Standard toothed saws are not suited to it.