Mitre and circular saw blades: teeth, bore and kerf

Diameter and bore: fit first

The diameter must match your saw, for example 165, 184, 190, 216, 254 or 305 mm. The bore is the centre hole; it must match the saw's arbor. Many mitre and larger saws use a 30 mm bore, and many 165 mm cordless circular saws use a 20 mm bore, such as the 165 x 20 mm blade in a Bosch GKS 18V-57 listing. Check your manual.

Reducing rings let a larger bore blade fit a smaller arbor, but only use rings supplied or approved by the blade or saw maker. Never fit a blade rated for a lower maximum speed than the saw's no load speed.

Tooth count

Fewer teeth cut faster and clear waste better but leave a rougher edge. More teeth cut more slowly and cleanly. For general purpose circular saw work, 24 teeth is the common supplied blade; for mitre saw trim work, 48 to 60 teeth gives cleaner ends.

Tooth shape

Alternate top bevel (ATB) teeth have angled tops that slice wood fibres cleanly, ideal for crosscuts. Flat top teeth chisel through wood along the grain, good for ripping. Triple chip grind (TCG) alternates a flat tooth and a chamfered one and is used for laminates, MDF and non-ferrous metal. Multi-material blades like Evolution's use special tooth geometry to cut steel and wood with the same blade.

Hook angle

Hook angle is how far the teeth lean forward. A positive hook bites aggressively, good for hand held circular saws ripping timber. On mitre saws, especially sliders, a low or negative hook keeps the blade from pulling itself into the work or climbing onto it. Many blades sold for mitre saws have a negative hook for that reason.

Kerf and cordless saws

Kerf is the width of cut the blade makes. A thin kerf blade removes less material, so the motor works less and a cordless saw makes more cuts per charge. The trade off is a little more flex in deep cuts. Many cordless circular and mitre saws ship with thin kerf blades, and Metabo describes its blade for the KGS 18 LTX BL 305 as a cordless cut blade.

Choosing for your saw

For a mitre saw used on skirting and flooring, fit a 48 to 60 tooth crosscut blade with a low or negative hook. For a circular saw on decking and framing, the supplied 24 tooth blade is fine; add a 40 to 48 tooth blade for sheet material. For a plunge saw on laminated boards, use a fine tooth blade with a splinter strip on the rail.

Compare saws in our mitre saw guide and cordless circular saw guide.

Keeping blades sharp and clean

Resin build up makes blades cut hot and burn the wood. Clean blades with a resin remover. A blade that burns, chips or needs force even when clean is blunt: have it resharpened or replace it. Burning and binding are covered in circular saw binding and burning.

Note:Always unplug the saw or remove the battery before changing blades. Fit the blade with the teeth pointing in the direction shown on the guard, tighten the flange as the manual says, and check the guard works before use. Wear gloves when handling blades and eye protection when cutting.

Multi-tool blades are different

Oscillating multi-tools use their own blade mounts, such as Starlock. See multi-tool blade fittings and our multi-tool guide.

Frequently asked questions

Can I use a circular saw blade in a mitre saw? Only if the diameter, bore and speed rating match, and the hook angle suits a mitre saw. A dedicated mitre saw blade is better.

How many teeth for cutting laminate flooring? A fine blade of around 60 teeth or more gives cleaner edges. Cut with the decorative face up on a mitre saw, or down on a hand held circular saw.

Why does my blade burn the wood? It is likely blunt, dirty or the wrong type, or the board is pinching the blade.

What does a 216 x 30 blade mean? It means a 216 mm diameter blade with a 30 mm centre bore.