Milwaukee cordless circular saws present a compatibility challenge because the M18 CCS55 uses a non-standard 15.87mm bore (which is imperial 5/8″). Most UK market blades come in 20mm or 16mm bore, so you’ll need either a reduction ring or Milwaukee-specific blades. This guide shows you what fits and what workarounds exist.
Milwaukee Cordless Circular Saw Models & Blade Specs
| Model | Blade Diameter | Bore Size | Notes |
|---|---|---|---|
| M18 CCS55 | 165mm | 15.87mm (5/8″) | Non-standard. See workarounds below. |
| M18 BLCS66 | 190mm | 30mm | Standard metric bore |
Recommended Circular Saw Blades
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The M18 CCS55 is the problematic model. Milwaukee used a 15.87mm (imperial 5/8″) arbor, which is not the same as 16mm metric. Most UK retailers stock 16mm or 20mm bore blades — neither of which fit directly onto a 15.87mm arbor.
Best Circular Saw Blades for Milwaukee Saws
For M18 BLCS66 (190mm × 30mm) — Straightforward
The BLCS66 uses standard metric specs: 190mm diameter with 30mm bore. Blades for this saw are available from any major supplier.
Best General Purpose: 40-Tooth Thin Kerf
Buy 190mm 40T thin kerf circular saw blades on Amazon
Best Fine Finish: 60-Tooth Thin Kerf
Buy 190mm 60T thin kerf circular saw blades on Amazon
For M18 CCS55 (165mm × 15.87mm) — Two Options
Since 15.87mm bore blades are very rare in the UK market, you have two practical choices:
Option 1: Buy Milwaukee-Branded Blades (Direct Fit)
Milwaukee makes blades with the correct 15.87mm bore. They cost a bit more but fit directly without any adapter. Check Milwaukee’s official UK supplier for blade options.
Search for Milwaukee circular saw blades on Amazon
Option 2: Use a 20mm-to-15.87mm Bore Reduction Ring
Buy a 20mm bore blade and use a bore reduction ring to step it down to 15.87mm. This works well and gives you access to the full range of UK market blades (typically cheaper than Milwaukee OEM).
Buy 20mm-to-15.87mm bore reduction rings on Amazon
Once you have a reduction ring, any 165mm × 20mm bore blade will work. This opens up Makita, Bosch Optiline, DeWalt, and budget brands like Diablo.
Buy 165mm × 20mm bore blades on Amazon
Why Does Milwaukee Use Imperial Bore?
Milwaukee is a US-owned brand and many of their cordless tools still use imperial (inch-based) specs even in UK models. The 15.87mm bore is exactly 5/8″ in imperial measurement. This is a legacy design choice that makes cross-compatibility frustrating for UK tradespeople who expect metric specs.
Which Option Should You Choose?
If you only own one M18 CCS55: Buy one Milwaukee-branded blade for convenience. Direct fit, no adapter needed.
If you own multiple Milwaukee tools or work with other brands: Buy a reduction ring once, then you can use any 165mm × 20mm blade. This gives flexibility and usually costs less overall.
If you want the best value long-term: The reduction ring option. A good quality ring costs £5–10, and you immediately gain access to brands like Bosch Optiline and Diablo that often outperform Milwaukee’s own blades at lower cost.
Related Pages
See the full circular saw blade compatibility guide for more on bore reduction rings and cross-brand compatibility. For battery and charger information, visit the Milwaukee M18 platform page.
Frequently Asked Questions
Can I use a 16mm bore blade in my M18 CCS55?
Technically, 16mm is close to 15.87mm and some blades might fit loosely. But don’t — a loose blade is a safety hazard. Use either a Milwaukee-specific blade or a 20mm blade with a proper reduction ring.
Why is 15.87mm different from 16mm?
Because 15.87mm is exactly 5/8 inch (imperial), whilst 16mm is metric. They’re not interchangeable — the 0.13mm difference means a loose fit.
Will a reduction ring work for the M18 CCS55?
Yes, a quality 20mm-to-15.87mm reduction ring works perfectly. Make sure it’s properly sized and secure before use.
Are Milwaukee blades more expensive than other brands?
Yes, typically 10–15% more than equivalent Bosch or Diablo options. If you use a reduction ring, you save money by accessing cheaper third-party blades.
How we compile this guide
We cross-reference compatibility details against manufacturer specifications where available, official tool manuals, and the physical standards that govern fitment (bore sizes, arbor diameters, voltage platforms, connector types). We prioritise primary sources over retailer listings, flag anything we can’t confirm, and re-verify the data on a regular cycle. Where we give a buying recommendation, we tell you the reasoning — not just the link. More on our method →