TCT Saw Blades: When to Sharpen, When to Replace

A new mid-range 254mm 60-tooth TCT (tungsten carbide-tipped) blade is $80 to $150 in Australia. Sharpening the same blade is $32 to $38. Most quality TCT blades can be sharpened 5 to 8 times over their working life before the carbide is too thin to grind. That's a $40 sharpen replacing a $100 blade five or six times. The maths is obvious.

Except it's not always that simple. Cheap import blades sharpen 2 to 3 times before they're done. Damaged plates can't be safely run regardless of carbide condition. And some specialty grinds (triple-chip, hi-ATB) are more expensive to sharpen than the equivalent budget blade is to replace.

This is the joiner's guide to when a TCT blade is worth saving and when it's not.

The five things to check before deciding

1. Carbide tip thickness: are the tips still meaningfully there, or worn down to the brazing line?
2. Plate condition: any cracks, warps, or heat-blueing?
3. Missing teeth: how many? Where on the blade?
4. Tooth profile and grind: TCG, ATB, FTG, combination?
5. Replacement cost: how much for a new blade of the same spec?

Get answers to all five before deciding. Most "replace it" calls in shops are made on visual dullness alone — and that misses the cases where the blade has plenty of carbide left and just needs a clean grind.

Carbide tip thickness

Look at any tooth edge-on. The carbide tip should stand visibly proud of the plate steel — typically 1mm to 2mm of tip thickness above the brazing line. If you can still see clear tungsten carbide above the braze, the blade has at least one more sharpen in it.

If the tips are worn down to almost level with the plate, the blade is finished. A sharpen at that point removes the last of the carbide and the blade comes back useless.

Quality blades (Freud, CMT, Forrest, Mafell) ship with thicker carbide and tolerate 5 to 8 sharpens. Budget blades (Bunnings own-brand, no-name imports) ship with thinner carbide and tolerate 2 to 3 sharpens. Match your expectation to the blade.

Plate condition

Three plate problems mean a blade must be replaced regardless of carbide condition:

• Cracks: any visible crack in the plate steel between the centre bore and the gullets. Cracks propagate under spinning load and the blade can shatter at speed. Bin it.
• Heat blueing: a blade that's been run too hot (forcing through wet timber, dull cutting, pinching) shows blue-purple colour in the steel. The temper is compromised and the blade can warp under load. Bin it.
• Warping: lay the blade flat on a known-flat surface. It should sit dead-flat with no rocking. Any warp shows up as a wobble in the cut and a wider-than-spec kerf.

None of these can be fixed by sharpening. We won't grind a cracked blade regardless of what the customer wants — the safety risk is too high.

Missing teeth

One missing tooth on a 60-tooth blade is fine — the blade still cuts cleanly. Two missing teeth: slightly noisier cut, still fine. Three or more missing teeth in a row: the blade is unbalanced at speed and the cut quality drops sharply. Replace.

The exception: low-tooth blades (24-tooth rip blades). A single missing tooth on a 24-tooth blade is more noticeable than on a 60-tooth. We'll quote individually for those.

For one or two scattered missing teeth, sharpening is still worth doing — the blade will perform well after the regrind. Just be aware that the next missing tooth (and the next) accumulate, and at some point the blade is past saving.

Tooth grind types and what they're for

• ATB (Alternate Top Bevel): general purpose. Crosscut and combination blades. 60 to 80 tooth typical. Most common on the Australian market.
• FTG (Flat Top Grind): rip blades. 24 to 40 tooth. Aggressive cut, rough finish.
• TCG (Triple-Chip Grind): laminate, ferrous metal, MDF. Tougher carbide profile, slower wear.
• Hi-ATB: melamine and laminate. Very steep ATB angle (30°+) for clean cut on coated boards.
• Combination: groups of ripping teeth alternated with crosscutting teeth. Compromise blade.

Triple-chip and Hi-ATB are more expensive to sharpen because each tooth has a different grind from the next — the sharpener has to set the machine up multiple times per blade. Budget Hi-ATB blades are sometimes cheaper to replace than sharpen; quality ones are still cheaper to sharpen.

The economics by tooth count and quality

• Budget 24-tooth 254mm rip blade ($25-40 new): sharpening at $32 is borderline. We'll do it but the replacement option is real.
• Mid-range 60-tooth 254mm combination ($60-120 new): sharpen at $32 every time. Sharpens 4 to 6 times over its life.
• Quality 80-tooth 254mm ATB ($150-300 new): sharpen always. The carbide is thicker, the plate is better, and the blade will outlast 3 budget blades.
• Premium TCG melamine/MDF blade ($250-500 new): sharpen always. Replacement cost is so high that even 3 sharpens pays for themselves several times over.
• Panel saw 315mm+ blade ($300-700 new): sharpen always. Cabinet shops with vertical panel saws run these for years on quarterly sharpens.

The hidden value: kerf consistency

A new blade and a sharpened blade cut the same kerf width if both are sharp. A worn-but-not-replaced blade cuts a wider, rougher kerf as the carbide flattens. For cabinet work where kerf consistency matters (panel cuts, sized stock, end-grain joinery), sharpening on a quarterly cycle keeps the kerf consistent across jobs. Some shops keep a "sharp" blade and a "running" blade for each saw and swap them — the running blade goes in for sharpening when the sharp blade comes out of rotation.

What workshop sharpening actually does

A professional saw-tooth grinder restores every tooth to spec individually. The machine:

• Grinds the top angle (the bevel across the top of the tooth).
• Grinds the face angle (the front face of the tooth — the hook).
• Grinds side clearance (the rake on either side of the tooth).
• Tests each tooth height against a reference.

The original profile (ATB, TCG, FTG) is preserved. The tooth count doesn't change. The blade comes back identical to its factory spec, just with less carbide on each tooth.

When DIY makes sense and when it doesn't

Hand-honing TCT teeth with a diamond file can extend the life of a blade between professional sharpens — a quick touch-up that takes 10 minutes. The limitation: you can only restore the cutting edge, not the geometry. Once the side clearances are worn, the kerf widens and a file won't fix it.

Bench-grinding TCT teeth on aluminium oxide wheels: don't. The wheel won't grind carbide effectively, you'll glaze the wheel, and you'll ruin the tooth geometry trying.

How to send blades in safely

Slip each blade into a cardboard sleeve (manufacturer's box if you still have it, or a custom sleeve we can mail you). Multiple blades stack in a rigid box with cardboard between them so the teeth don't touch. Never a soft mailer — the teeth will punch through. Australia Post Express is the fastest option; for 5+ blades, courier freight is often cheaper than multiple satchels.

Our circular saw blade sharpening service handles TCT, hi-ATB, TCG and FTG blades from 160mm hand-held through to 350mm+ panel saws. From $25 per blade with 2 to 3 day workshop turnaround. Joinery shops and cabinet-makers welcome — bulk pricing on 5+ blades.

For instant pricing, place an order online. For a quote on specialty blades or bulk shop work, contact us first.

The bottom line

Mid-range and quality TCT blades are almost always worth sharpening — typically 5 to 8 times before replacement. Budget blades sharpen 2 to 3 times. Cracked, blued, or warped plates are bin-only. Two or more missing teeth in a row is replacement territory. Everything else: sharpen first, replace as a last resort, and you'll spend 25 to 30 percent of the cost of running new blades over the life of the workshop.