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Max-Prop Easy feathering propellers in stainless steel: two, three and four blades, 12 to 24 in, for shafts 3/4 to 1 3/4 in, plus SailDrive models, anodes and spares. Click here to read more.

Max-Prop Feathering Propellers: Blade Count, Shaft Size and SailDrive

A feathering propeller turns its blades edge-on to the flow when you sail, so there is little drag under canvas, and pitches them back to drive the boat when you motor. The propellers in this range are stainless-steel Easy models: each bolts onto the shaft, and the pitch can be changed without a haul-out. This page is the brand entry point. The propellers themselves sit in three collections by blade count, and the anodes, grease and fittings that keep them running have their own collections.

Where to Find Each Max-Prop Product
  • Two blades: Easy 2-blade in 12 to 18 in blade diameter, for shafts 3/4 to 1 in (19.05 to 25.4 mm) and 3/4 to 1 1/8 in (19.05 to 28.6 mm). Max-Prop lists it for racing boats and smaller cruisers, with very low drag under sail. Start with the 16 in.
  • Three blades: Easy 3-blade in 13 to 23 in, for shafts from 3/4 in up to 1 3/4 in (44.4 mm), plus six SailDrive models. Listed for 24 to 55 ft medium-displacement cruisers. See the 20 in for 3/4 to 1 1/4 in shafts.
  • Four blades: Easy 4-blade in 14 to 24 in, for shafts 3/4 to 1 3/4 in, plus six SailDrive models. Listed for 40 to 70 ft cruisers of medium to heavy displacement, with very smooth running. See the 22 in for 1 1/4 to 1 1/2 in shafts or the 24 in for 1 1/2 to 1 3/4 in shafts.
  • Anodes: zinc anodes in sizes from 2 31/64 in (63 mm) to 6 19/64 in (160 mm), singly or boxed, plus the screw kits. Individual anodes do not come with screws.
  • Maintenance and spares: combo boxes by hub diameter, Zerc plugs and risers, Lubriplate #130-AA grease and the grease kit.
How to Choose the Right Easy
  • Shaft diameter first. Each listing gives the shaft range it fits, from 3/4 in (19.05 mm) to 1 3/4 in (44.4 mm). Measure the shaft, then pick the hub that covers it. The first number in the part number is the hub diameter in mm (78, 85, 90, 99 or 110), which is also how the combo boxes are listed.
  • Blade count by use. Two blades give the lowest drag under sail. Three blades add forward power and run much smoother, with slightly more drag than a two-blade. Four blades are listed for outstanding forward power and very smooth running on larger, heavier cruisers.
  • Diameter and pitch. The listings give blade diameter but no boat-length chart per diameter. Diameter and pitch are matched to engine, gear ratio and boat, and the pitch is then trimmed so the engine reaches its rated rpm at full throttle. Our engine and propellers category guide covers the inputs.
  • SailDrive. The SailDrive propellers are separate models, not shaft sizes. The collection has Easy 3-blade and 4-blade versions with 15 to 20 in blades, such as the 4-blade 20 in SailDrive. There is no 2-blade SailDrive in the range.
Performance Figures Max-Prop Quotes
  • In forward, 96% of the efficiency of a fixed-blade propeller of the same diameter and pitch; the 4% loss can usually be eliminated by matching the pitch to the boat and engine.
  • Under sail, about 15% more sailing speed than with a fixed propeller, with the largest difference in light air.
  • In reverse, 80% more power than a comparable fixed-blade propeller, using the same leading edge in both directions for the same thrust ahead and astern.

These are Max-Prop's own figures from the product listings; your result depends on the boat, the engine and how well the pitch is set.

Keeping a Max-Prop Running

The listings say a Max-Prop should be greased once a year, in or out of the water, and recommend Lubriplate 130-AA grease. Zinc anodes should be kept in good condition and replaced at least once a year. If the boat stays afloat all year, a diver checking the anodes can grease the propeller at the same visit.

Who It's For

Sailors who want less drag under sail and the same thrust ahead and astern, owners replacing an existing feathering propeller who need the shaft and hub to match, and SailDrive boats that need the dedicated model.

Frequently Asked Questions

Which Max-Prop Easy fits my shaft?
Match the shaft diameter to the range in the listing: 3/4 to 1 in, 3/4 to 1 1/8 in, 3/4 to 1 1/4 in, 1 1/4 to 1 1/2 in or 1 1/2 to 1 3/4 in. Then choose the blade diameter. Two-blades stop at 1 1/8 in shafts; the three- and four-blades cover the larger shafts.

Should I choose two, three or four blades?
Two blades if sailing drag matters most, as on racing boats and smaller cruisers. Three blades for added forward power and smoother running on 24 to 55 ft medium-displacement cruisers. Four blades for 40 to 70 ft cruisers of medium to heavy displacement. The size bands overlap, so shaft and engine decide.

Can I change the pitch without hauling out?
Yes, according to the listings. If the engine reaches too much or too little rpm at full throttle, set the pitch higher or lower; the propeller does not have to be taken apart and the adjustment can be made in the water.

Is there a Max-Prop for a SailDrive?
Yes, in 3 and 4 blades, with 15 to 20 in blades. The listings give no shaft size for these models, so check your SailDrive model against the listing before ordering.

How often should I grease the propeller and change the anodes?
Grease once a year and replace the zinc anodes at least once a year, per the listings. The grease kit, the grease and the anodes are in the maintenance and anodes collections; the combo boxes are listed by hub diameter and the anodes by size.