Description
Special features
- Helical gearing between the blades ensures a synchronized folding mechanism.
- Protective cover over the gearing.
- Easy replaceable anode
- Large shock absorbers for a quiet opening of the propeller.
- Special inner hub to protect the saildrive and gearbox from the propeller impact.
- Mounting screws are pre-applied with Loctite for mounting above as well as underwater.
- Water lubricated – no need for maintenance.
Propeller sizes
The 4-blade propellers for shaft installation is available in diameters of 15″ to 27″ – all in a wide range of pitches.
To be supplied for both LEFT and RIGHT turning shafts.
Compatible with…
The Flexofold propellers have a 100% fit on all common shaft diameters with ISO, SAE or IMP cones
- ISO (European standard) = 1:10 cone
- SAE (US standard) = 1:16 cone
- IMP (British standard) = 1:12 cone
Tech.
Operating Instructions
- When handling the assembled propeller, avoid being pinched by opening or closing blades.
- Do not operate the propeller when close to people or animals in the water.
- Stop the engine immediately if any strange sounds or vibrations are noticed coming from propeller.
- Check that the propeller functions in both forward and reverse before each voyage.
- Shift gears at idling RPMs only.
- When sailing, the propeller must be stopped for the blades to fold/close.
- With a mechanical transmission; stop the engine and put the transmission in reverse gear to prevent the propeller from turning.
- With hydraulic transmission; while boat is moving forward under sail or due to momentum and engine is still running, engage reverse gear and shut down the engine.
Maintenance
The only maintenance required is to keep the propeller clean.
The pivot pins and gears are water lubricated, however, adding waterproof grease to the moving parts will help the folding and unfolding.
Disassembly
Disassembling your Flexofold propeller is just as easy as mounting it. Simply follow the mounting instruction in reverse order.
Flexofold Prop Puller

If you have a shaft installation, the hub might be stuck to the shaft cone.
In that case, we recommend that you use a puller.
The Flexofold Prop Puller is designed for use on all Flexofold 2-, 3- and 4-blade propellers.
You can buy the puller directly from Flexofold under Spare Parts.
How to use the Flexofold Prop Puller

Simply place the puller behind the pivot pins. A loose fit of the locking screws will prevent the pivot pins from falling out.
Now, turn the screw against the shaft end to pull off the hub.
Heating the hub where it´s attached to the shaft cone, will often help loosen the grip.
Propeller dimensions
Please be aware:
- Unlike the general perception, even as little as 8-10 mm of free space between propeller and hull will be fine. However, this of course depends on the specific hull shape and less clearence will normally increase propulsion noise.
- Due to the nature of the propeller construction, folding blades are positioned further aft than a fixed propeller (see hub length) and thereby leave more space between shaft and hull.
How to calculate the total length of the folded propeller:

Hub length, ISO standard shaft
Hub length (A), 2-blades |
Hub length (A), 3-blades up to 23″ |
Hub length (A), 3-blades >22″ and 4-blades |
22 mm shaft, 1:10 taper = 88 mm ≈ 3.5″ |
25 mm shaft, 1:10 taper = 120 mm ≈ 4 47/64″ |
35 mm shaft, 1:10 taper = 148 mm ≈ 5 53/64″ |
25 mm shaft, 1:10 taper = 110 mm ≈ 4 3/8″ |
30 mm shaft, 1:10 taper = 136 mm ≈ 5 23/64″ |
40 mm shaft, 1:10 taper = 157 mm ≈ 6 3/16″ |
30 mm shaft, 1:10 taper = 130 mm ≈ 5 1/8″ |
35 mm shaft, 1:10 taper = 146 mm ≈ 5 3/4″ |
45 mm shaft, 1:10 taper = 196 mm ≈ 7 23/32″ |
22 mm shaft, 1:10 taper = 88 mm ≈ 3.5″ |
40 mm shaft, 1:10 taper = 156 mm ≈ 6 9/64″ |
50 mm shaft, 1:10 taper = 206 mm ≈ 8 1/8″ |
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45 mm shaft, 1:10 taper = 196 mm ≈ 7 23/32″ |
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Hub length, SAE standard shaft
Hub length (A), 2-blades |
Hub length (A), 3-blades up to 23″ |
Hub length (A), 3-blades >22″ and 4-blades |
3/4″ shaft, 1:16 taper = 100 mm ≈ 4.0″ |
1″ shaft, 1:16 taper = 136 mm ≈ 5 23/64″ |
1 1/2″ shaft, 1:16 taper = 202 mm ≈ 8″ |
7/8″ shaft, 1:16 taper = 115 mm ≈ 4.5″ |
1 1/8 shaft, 1:16 taper = 146 mm ≈ 5 3/4″ |
1 3/4″ shaft, 1:16 taper = 210 mm ≈ 8 9/32″ |
1″ shaft, 1:16 taper = 130 mm ≈ 5 1/8″ |
1 1/4″ shaft, 1:16 taper = 156 mm ≈ 6 9/64″ |
2″ shaft, 1:16 taper = 275 mm ≈ 10 53/64″ |
1 1/8″ shaft, 1:16 taper = 142 mm ≈ 5 19/32″ |
1 1/2″ shaft, 1:16 taper = 194 mm ≈ 7 41/64″ |
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1 1/4″ shaft, 1:16 taper = 157 mm ≈ 6 3/16″ |
1 3/8″ shaft, 1:16 taper = 177 mm ≈ 7″ |
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1 3/4″ shaft, 1:16 taper = 210 mm ≈ 8 9/32″ |
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Hub length, IMP standard shaft
Hub length (A), 2-blades |
Hub length (A), 3-blades up to 23″ |
Hub length (A), 3-blades >22″ and 4-blades |
3/4″ shaft, 1:12 taper = 96,5 mm |
1″ shaft, 1:12 taper = 116 mm ≈ 4 37/64″ |
1 3/4 shaft, 1:12 taper = 196 mm ≈ 7 23/32″ |
1″ shaft, 1:12 taper = 110 mm ≈ 4 3/8″ |
1 1/4″ shaft, 1:12 taper = 136 mm ≈ 5 23/64″ |
40 mm shaft, 1:10 taper = 157 mm ≈ 6 3/16″ |
1 1/4″ shaft, 1:12 taper = 129 mm ≈ 5 5/64″ |
1 1/8 shaft, 1:12 taper = 120 mm ≈ 4 47/64″ |
45 mm shaft, 1:10 taper = 196 mm ≈ 7 23/32″ |
Hub length (A), saildrive
2-blades |
3-blades |
135 mm |
135 mm |
Blade length (B)
2-blades |
3-blades |
4-blades |
12″ = 139 mm ≈ 5 31/64″ |
14″ = 151 mm ≈ 6″ |
25″ = 275 mm ≈ 10 53/64″ |
13″ = 152 mm ≈ 6″ |
15″ = 163 mm ≈ 6 27/64″ |
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14″ = 165 mm ≈ 6.5″ |
16″ = 176 mm ≈ 6 15/16″ |
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15″ = 177 mm ≈ 7″ |
17″ = 189 mm ≈ 7 29/64″ |
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16″ = 190 mm ≈ 7.5″ |
18″ = 202 mm ≈ 7 61/64″ |
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17″ = 203 mm ≈ 8″ |
19″ = 216 mm ≈ 8 1/2″ |
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18″ = 215 mm ≈ 8 15/32″ |
20″ = 227 mm ≈ 8 15/16″ |
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22″ = 282 mm ≈ 11 7/64″ |
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Propeller diameter:
12″ = 305 mm |
13″ = 330 mm |
14″ = 356 mm |
15″ = 381 mm |
16″ = 406 mm |
17″ = 432 mm |
18″ = 457 mm |
19″ = 485 mm |
20″ = 508 mm |
21″ = 533 mm |
22″ = 559 mm |
24″ = 610 mm (3-blade propeller) |
24″ = 625 mm (4-blade propeller) |
25″ = 635 mm |
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