Cutless Bearing vs Cutlass Bearing: Two Spellings, One Part
Shopping for a cutless bearing and finding cutlass bearings instead — or the other way round? Relax: they're the same water-lubricated propeller shaft bearing. Here's where the two spellings come from, and how to match the right size no matter which brand is in your boat today.
The short answer
A cutless bearing and a cutlass bearing are the same part — a water-lubricated shaft bearing with a grooved liner that sits in the stern tube, strut, P-bracket or skeg. Seawater flows along the grooves, the spinning propeller shaft rides on a thin film of water, and grit gets flushed through instead of grinding the shaft. No grease, no oil — water does the lubricating. The only difference between the two names is trademark law and habit.
If you're new to the part itself, our plain-English guide to what a cutlass bearing is covers how it works in more detail.
Cutless® is a trademark; cutlass is the generic term
Cutless® is a registered trademark of Duramax Marine, used for its well-known Johnson Cutless range of water-lubricated bearings. As happens with successful trademarks, the brand name became everyday shorthand for the product itself. In Australia and the UK, the generic spelling cutlass bearing is the standard — it's what most local yards, chandleries and surveyors write. You'll also see cutlas and cuttless in the wild; every one of them refers to the same part.
To be clear about what we sell: Cutlass Bearings Australia is an independent Australian reseller of genuine Exalto bearings, manufactured in the UK. Exalto is an equivalent water-lubricated bearing range — we don't stock or sell Johnson Cutless product, and we make no claim to. If your boat currently runs a Johnson Cutless bearing, an Exalto bearing of the same dimensions is a direct swap.
| Term | What it refers to |
|---|---|
| Cutless® | Registered trademark of Duramax Marine — the Johnson Cutless range of water-lubricated shaft bearings |
| Cutlass bearing | Generic Australian/UK term for the same type of bearing, any brand |
| Cutlas / cuttless | Common misspellings — still the same part |
| Exalto | Genuine UK-made equivalent range — the brand we stock in Australia |
How to cross-reference any brand by dimensions
Water-lubricated shaft bearings interchange across brands by size, not part number. Ignore whatever code is stamped on the old bearing and work from three measurements:
- Shaft (inside) diameter — the I/D the shaft runs in
- Housing (outside) diameter — the O/D pressed into the tube or strut
- Overall length — standard marine proportions make this 4× the shaft diameter
Match those three numbers on our cutlass bearing size chart and the fit works regardless of which brand is in the boat now. Our step-by-step measuring guide shows exactly where and how to take each measurement.
One caution on fits: Exalto publishes the I/D and O/D as tolerance ranges. Your shaft must sit below the bottom of the I/D range — that gap is the designed running clearance — and your housing must sit above the top of the O/D range, which gives the interference fit that holds the bearing in place. Never add clearance yourself; it's already engineered in.
Exalto's part codes simply describe the units used: MPSF50 is fully metric, MIPSF40 is a metric shaft in an imperial housing, and IPSF20 is fully imperial. Handy to know, but you never need to decode them — matching dimensions on the chart does the job.
Why Australians search both spellings
Many boats in Australian waters were built or repowered in the US, where the Cutless® name dominates — their manuals and old invoices say cutless bearing. Local yards and UK-built boats say cutlass. Add American forums and videos to the mix and most owners end up typing both at some point, which is fine: either spelling lands you on the same part.
Whichever you type, a worn bearing announces itself the same way — rumble or clunk under power, vibration through the hull, and perceptible movement when you lever the shaft at the bearing. Our cutlass bearing replacement guide covers how to check it and what the job involves.
Buying a cutless bearing in Australia
We hold Australian stock of 215 sizes of genuine Exalto marine shaft bearings, covering shaft diameters from 3/4″ (20 mm) up to 4″ (100 mm), in four materials:
- Phenolic — the modern default and our biggest seller: low friction, long life in clean saltwater, excellent vibration damping
- Rubber — nitrile with longitudinal water grooves that flush sand and silt through; the pick for sandy or debris-laden water
- Brass-shelled — a phenolic liner in a naval brass shell, for worn or oversize housings that need a metal shell's grip
- GRP — a glass-reinforced polyester shell that bonds directly into fibreglass stern tubes (never into metal ones)
Prices run from $115 to $2,395 across the range, with most common sizes landing roughly between $200 and $500 — GST is included in every price. Order an in-stock size before 2pm AEST and it's dispatched the same day with free Express Post Australia-wide; anything not on the shelf ships in 3–4 weeks.
Cutless bearing FAQs
Is there a difference between a cutlass bearing and a cutless bearing?
No — they're the same water-lubricated propeller shaft bearing. Cutless® is a registered trademark of Duramax Marine (the Johnson Cutless range), while cutlass bearing is the generic term used in Australia and the UK. Both names, and misspellings like cutlas and cuttless, refer to the same part.
Can I replace a Johnson Cutless bearing with an Exalto bearing?
Yes. Water-lubricated shaft bearings interchange by dimensions, not brand. Measure the shaft diameter (I/D), housing diameter (O/D) and overall length, then match those three numbers on our size chart. An Exalto bearing with the same dimensions is a direct replacement.
Which spelling is correct — cutlass or cutless?
Both are in use. Cutless® is correct when referring to Duramax Marine's trademarked Johnson Cutless product; cutlass bearing is the standard generic spelling in Australia and the UK. Suppliers and yards understand either.
How do I know which size cutless bearing I need?
Measure three numbers: shaft diameter, housing bore and overall length — the standard length is four times the shaft diameter. Our measuring guide shows how to take each one, and the size chart matches your measurements to the right Exalto bearing.
Find your size — Australian stock, free Express Post
Whichever spelling brought you here, the next step is the same: match your three measurements on the size chart, or browse by material. Not sure what you're looking at? Email us your measurements — even rough numbers — and we'll confirm the exact bearing before you order. In-stock sizes ordered before 2pm AEST are dispatched the same day, with free Express Post anywhere in Australia.