Saw blade tooth geometries: ATB, TCG, DTCG and flat top

The profile determines how the tooth enters the material

Before looking at how many teeth a blade has, examine the individual tooth. Cutting-edge shape determines where first contact occurs, which in turn affects whether fibres are severed progressively or torn away.

An inclined edge contacts the workpiece at one corner and cuts progressively, rather like a knife. A flat edge contacts across its full width and pushes straight through: it removes material efficiently but leaves a different exit edge.

Hook angle adds another variable. Across the catalogue it ranges from +15° on some panel blades to −6° on blades for thick laminated panels and non-ferrous metals. A positive angle pulls into the cut; a negative angle directs more force down towards the machine table.

ATB: the reference geometry for wood

ATB is the most widespread wood geometry because the key task is to sever fibres before lifting them. The leading corner of the bevel does exactly that.

The bevel and hook angle vary by application. LU2A uses a 10° or 15° bevel depending on the product code with a positive 15° hook angle. Crosscut-only LU2C uses a 15° bevel but a much less aggressive positive 5° hook angle and therefore requires a more controlled feed.

Profile and moulding blades can use a steeper bevel. LU1I combines ATB 20° with a 10° hook angle for painted or coated surfaces where edge chipping cannot be repaired. At 300 mm it is available as Z96 and Z112: tooth counts that would be excessive on a thick panel but appropriate for a thin profile.

ATB can also include a chip limiter: a shoulder in front of the cutting edge that limits chip thickness per tooth. It is used where machine feed is imposed rather than controlled by the operator, including multiripping applications.

TCG: two teeth performing one operation

In a triple-chip grind the teeth work in pairs. The trapezoidal tooth opens and roughs the centre of the cut; the slightly lower flat tooth widens it to both edges and clears the bottom.

The arrangement protects vulnerable cutting corners. In laminate or aluminium profiles, those corners are often the first points to wear, so dividing the load between two profiles can extend the interval between sharpenings.

Hook angle varies with application. LU3D for two-sided laminated panels with a scoring blade uses 5° or 10° depending on code and offers Z72, Z84 and Z96 at 300 mm for different panel thicknesses. LU5C for extruded sections over 3 mm uses −6° and Z72 at the same diameter.

The sign of the hook angle affects the direction of cutting force. A negative angle helps press the workpiece towards the table rather than lifting it, which is important on mitre saws cutting from above.

Flat-top and double-trapezoidal teeth

The flat-top tooth is simple and remains highly efficient where material removal matters most. LU1E uses it for ripping with a positive 15° hook angle and thin kerfs from 2.5 to 3 mm. Less removed material means less waste and lower power demand; at 300 mm the tooth counts are Z24 and Z28.

On multiripping blades, flat-top teeth can be combined with stabilising teeth and a positive 12° hook angle. The blade must remain stable within a stack of material, so stability matters more than a fine crosscut finish.

DTCG is a different system. LU6A uses double-trapezoidal teeth in TF30 carbide for dry cutting steel, with 0° hook angle and a 12° bevel. At 355 mm it is available as Z72 and Z90, with a maximum speed of 1,600 rpm compared with the 5,500 rpm general reference near that diameter.

Wood-cutting guidelines and tooth-count formulas do not apply to this application. The workpiece must be clamped rigidly to prevent carbide damage from an irregular first contact.