Circular saw blade compatibility is more complex than many other tool attachments because two dimensions have to match: the diameter of the blade and the bore size (the hole in the centre). Get either one wrong and the blade won’t fit safely. This guide walks you through both, covers all the major brands, and explains what to do if your blade diameter is right but the bore doesn’t match.
Key Compatibility Factors
When choosing a circular saw blade, you need to check two things:
1. Blade Diameter — measured in millimetres. Your saw’s manual will specify exactly which size(s) it accepts. Most cordless circular saws take 140–190mm blades, with larger corded models going up to 210mm or beyond.
2. Bore Size — the hole in the centre of the blade where it mounts on the arbor (the shaft that spins the blade). Common sizes are 16mm, 20mm, 25mm and 30mm. If the bore is too big, the blade will be loose and wobble dangerously. If it’s too small, it won’t fit on the arbor at all.
Both dimensions must match your saw exactly. You can’t just assume that because a blade is the right diameter, it will fit.
Common Blade Sizes in the UK
| Blade Diameter | Common Bore Sizes | Typical Saw Size |
|---|---|---|
| 140mm | 20mm, 16mm | Very small compact saws (rare) |
| 165mm | 20mm, 16mm, 15.87mm | Handheld cordless (most common) |
| 185mm | 20mm, 16mm | Mid-range handheld |
| 190mm | 30mm, 20mm | Larger handheld, table saws |
| 210mm | 30mm, 25mm | Table saws, track saws |
| 216mm | 30mm | Table saws |
| 250mm | 30mm, 25.4mm | Large table saws, walk-behind concrete saws |
Brand Compatibility Matrix
Here’s what each major cordless circular saw model actually takes:
| Brand & Model | Blade Diameter | Bore Size | Platform |
|---|---|---|---|
| Makita DHS680Z | 165mm | 20mm | 18V LXT |
| Makita DHS710Z | 190mm | 30mm | Twin 18V LXT |
| DeWalt DCS391 | 165mm | 20mm | 18V XR |
| DeWalt DCS570 | 184mm | 16mm | 18V XR |
| DeWalt DCS565 | 165mm | 20mm | 18V XR |
| Milwaukee M18 CCS55 | 165mm | 15.87mm (5/8″) | M18 |
| Milwaukee M18 BLCS66 | 190mm | 30mm | M18 FUEL |
| Bosch GKS 18V-57 | 165mm | 20mm | 18V CoolPack |
| Bosch GKS 18V-68 GC | 190mm | 30mm | 18V CoolPack |
| Ryobi RWSL1801M | 165mm | 16mm or 20mm | ONE+ 18V |
Critical note for Milwaukee: The M18 CCS55 takes a 15.87mm bore (which is 5/8″ in imperial). This is not the same as 16mm or 20mm. Most UK supplier blades come in 20mm bore. You’ll either need to buy Milwaukee-specific blades or use a reduction ring.
Bore Size Reduction Rings
If your blade diameter is correct but the bore is too large, a bore reduction ring (also called a bush or arbor adapter) can help. For example, if you have a 165mm blade with a 20mm bore but your saw’s arbor is only 16mm, a 20mm-to-16mm ring steps the blade down.
Common reductions available:
- 30mm to 20mm
- 30mm to 16mm
- 25mm to 20mm
- 20mm to 16mm
- 20mm to 15.87mm (for Milwaukee M18 CCS55)
Safety note: Always use a properly fitted reduction ring. A loose blade is a safety hazard. If the ring feels even slightly loose, don’t use it. Check that the ring is made for the exact bore sizes you need — not all rings are universal.
Buy bore reduction rings on Amazon
Tooth Count Guide
Once you’ve got the diameter and bore sorted, choose the right tooth count for your material:
| Tooth Count | Best For | Cut Speed | Finish |
|---|---|---|---|
| 24T (coarse) | Framing lumber, rough cuts, demolition | Fast | Rough |
| 40T (general purpose) | General carpentry, plywood, softwood | Medium | Good |
| 48T (fine) | Laminate, MDF, hardwood, finish cuts | Slow | Excellent |
| 60T (very fine) | Thin materials, veneer, melamine, polished finish | Very slow | Excellent |
For general cordless work, a 40T blade is the sweet spot — fast enough for production work but with a clean enough finish for customer-facing cuts. For fine joinery, step up to 60T thin kerf.
Thin Kerf vs Standard Kerf
Kerf is the thickness of the cut — the material the blade removes. A thin kerf blade (typically 2.4–2.6mm) removes less material than a standard kerf blade (3.0–3.2mm).
Why it matters for cordless tools:
- Less resistance — thin kerf blades put less load on the motor, so you get longer runtimes
- Less power needed — easier for the saw to push through dense materials
- Cleaner cuts — less vibration, less splinter
- Less waste — useful for expensive materials or ripping panels
The downside is that thin kerf blades are slightly less durable and can wander on very thick hardwood. For general cordless work, thin kerf is worth buying.
Blade Types by Material
| Material | Recommended Tooth Count | Blade Type |
|---|---|---|
| Softwood (pine, fir, spruce) | 24–40T | Standard kerf HCS or bi-metal |
| Hardwood (oak, ash, walnut) | 40–60T thin kerf | Carbide-tipped |
| Plywood | 40–60T | Thin kerf, minimal splinter blade preferred |
| Laminate | 60–80T | Thin kerf carbide, fine-tooth |
| Melamine | 60T+ | Thin kerf, upcut preferred to avoid chipping top face |
| Fibre cement board | 40T carbide | Dust collection essential — these are abrasive |
| Aluminium | 40–60T | Non-ferrous metal blade, TCG tooth geometry |
Where to Buy Circular Saw Blades UK
Buy circular saw blades on Amazon UK
Popular reliable brands include Makita (OEM), Bosch Optiline, DeWalt, Milwaukee, and budget-friendly options like Diablo (owned by Freud) and Trend.
Frequently Asked Questions
Can I use a larger diameter blade in my circular saw?
No. Larger blades spin at a lower RPM for the same tool, which reduces cutting speed and can make the blade bind or kick back. Always match the exact diameter your saw is rated for.
My blade diameter is right but the bore doesn’t fit. What do I do?
Use a bore reduction ring if the bore is too large. If the bore is too small (the blade won’t fit over the arbor at all), you need a different blade — there’s no adapter that makes a smaller bore larger.
Are all 165mm blades the same?
No — they vary by tooth count, kerf, material (HCS, bi-metal, carbide-tipped), and bore size. Check all three specs before buying.
What’s the difference between HCS, bi-metal and carbide-tipped blades?
HCS (high-carbon steel) is cheapest but dull quickly. Bi-metal lasts 2–3x longer and handles knots and nails better. Carbide-tipped lasts longest and stays sharp on hardwood and abrasive materials. For professional cordless work, carbide-tipped is worth the extra cost.
Why does my Milwaukee M18 CCS55 need a special bore size?
Milwaukee designed that model with a 15.87mm (5/8″) arbor, which is imperial sizing. Most UK market blades are metric (16mm or 20mm). You can use a 20mm bore blade with a 20-to-15.87mm reduction ring, or buy Milwaukee-branded blades which fit directly.
Which blade should I start with if I do mixed work?
A 40-tooth thin kerf blade in the diameter your saw takes. It’s the best all-rounder for wood, plywood, and general site work. Once you know your specific materials, build a small collection: 24T for framing, 40T for general, 60T for fine work.