Propeller Chart & Recommendations

Published by George & Peter,

The most difficult choice in Rc boating is picking the perfect prop!

Propellers come in many different materials, listed from softest to hardest are Plastic, Aluminum, Carbon Fiber, Beryllium Copper, and Stainless Steel. The best performance will be from a perfectly balanced and sharpened Beryllium Copper or Stainless Steel prop. You'll notice the the bellow pictures of the Beryllium Copper & Stainless steel props are very dull, that's because these props come as castings and need to be filed, sharpened & balanced. See How to Balance and Sharpen Article for more information. For the best "bang for the buck" and no work balancing & sharpening, look at the Graupner Carbon Filler Propellers. They are great for Sport running.


Plastic
Carbon Fiber
Beryllium Copper
Stainless Steel

When searching for the perfect prop we need to balance three important factors, Top Speed, heat buildup in Batteries, Motor & ESC (electronic speed control) and the ability for the hull to get up on plane. Most Electric kit boats come with props that will work in a wide range of applications. Changing to the right prop with a kit boat will almost always yield a performance increase. Always start out with a smaller prop and work up to the optimum size. Never put to large of a prop an electric boat first. This will lead to burnt up ESC, Motor or Batteries. Bigger is not better in every case, this is particularly true in high RPM motors. To run at their best efficiency they need to spin fast. Too large of a prop will not allow the prop to reach its best RPM efficiency range and will cause heat build up in the ESC, Motor or Batteries. On the first run with the new prop, run it at full speed for twenty to thirty seconds, observe how quickly the boat got on plane and the top speed, the pull the boat out of the water and to test for heat, have an adult give the motor the 5 second test. Which is, hold your finger on the motor for 5 seconds. If its so hot you can't hold it for 5 seconds, its too hot. Allow to cool fully before running again! If everything is cool or warm, keep doing this test until the pack starts to dump. DO NOT RUN THE PACK TO 0% CAPACITY! This will cause lots of heat and ruin your test results. At the end of the run if things are warm but not hot swap to a larger prop. With Nitro, running too small a prop may allow the engine to spin at to high of an RPM and blow the engine!

Things to remember

  • First move the COG (center of gravity) forward or backward to get on plane quicker. For most monos and catamarans 30% forward of the transom is a good place to start. To check the COG put your left and right finger 1/3 of the hull length forward of the transom and have the boat balance in your fingers.
  • If the boat will not come on plane, and the motor seems to be at full RPM the prop is cavitating. You may need a larger prop with more thrust to get on plane.
  • A well balanced and sharpened prop will always spin at higher RPM allowing a higher top speed!
  • Always monitor motor or engine heat! Cooler is better. To much heat kills!
  • Different water conditions will achieve different results. When comparing test results from a different day make sure the water and wind conditions where similar!
The following Chart is from Octura's line up of Propellers. There are other companies that offer propellers but Octura seems to have the widest range of sizes for Electrics. Most props are left hand props, except for the ones labeled with an "R" after the prop Size.

To figure out how far a particular prop will travel, we need to know the total pitch, which is the diameter x pitch.
If we take into example the first prop listed(930), 1.18"diameter X .9 pitch = 1.062"

So the total pitch of the 930 prop is 1.062 inches. Every time the prop shaft turns once the boat will move 1.062 inches. This is with no slip in a perfect world. Well it isn't a perfect world so as a rule of thumb,

  • A Mono hull will slip 25%
  • A Catamaran of scale Hydro 20%
  • A Rigger about 15%
This is assuming that the hulls are well balanced and running free.

Click here for a Tool to make some top speed estimates!
Octura Propellers.
Prop#
Diameter
Pitch
Fits shaft size
Plastic
Al
BC
930
30mm (1.18")
0.9 x 1.18 =1.062"
1/8"
x
x
937/3
37mm (1.48")
0.9 x 1.48 =1.332"
1/8"
x
x
955/3
55mm (2.17")
0.9 x 2.17 =1.953"
3/16"
x
0955/3R
55mm (2.17")
0.9 x 2.17 =1.953"
3/16"
x
977
77mm (3.03")
0.9 x 3.03 =2.727"
1/4"
x
1240
40mm (1.57")
1.2 x 1.57 =1.884"
3/16"
x
1240/3
40mm (1.57")
1.2 x 1.57 =1.884"
3/16"
x
1245
45mm (1.77")
1.2 x 1.77 =2.124"
3/16"
x
1250
50mm (1.97")
1.2 x 1.97 =2.364"
3/16"
x
1250R
50mm (1.97")
1.2 x 1.97 =2.364"
3/16"
x
1255
55mm (2.17")
1.2 x 2.17 =2.604"
3/16"
x
1270
70mm (2.76")
1.2 x 2.76 =3.312"
3/16"
x
1337/3
37mm (1.48")
1.3 x 1.48 =1.924"
3/16"
x
1427
27mm (1.07")
1.4 x 1.07 =1.498"
1/8"
x
x
1435
35mm (1.38")
1.4 x 1.38 =1.932"
3/16"
x
1440
40mm (1.57")
1.4 x 1.57 =2.198"
3/16"
x
1445
45mm (1.77")
1.4 x 1.77 =2.478"
3/16"
x
1450
50mm (1.97")
1.4 x 1.97 =2.758"
3/16"
x
x
1455
55mm (2.17")
1.4 x 2.17 =3.038"
3/16"
x
x
1455/3
55mm (2.17")
1.4 x 2.17 =3.038"
3/16"
x
1457
57mm (2.24")
1.4 x 2.24 =3.136"
3/16"
x
x
1457R
57mm (2.24")
1.4 x 2.24 =3.136"
3/16"
x
1457/3
57mm (2.24")
1.4 x 2.24 =3.136"
3/16"
x
1460
60mm (2.36")
1.4 x 2.36 =3.304"
3/16"
x
x
1462
62mm (2.44")
1.4 x 2.44 =3.416"
3/16"
x
x
1462R
62mm (2.44")
1.4 x 2.44 =3.416"
3/16"
x
1465
65mm (2.56")
1.4 x 2.56 =3.584"
3/16"
x
x
1467
67mm (2.64")
1.4 x 2.64 =3.696"
1/4"
x
1470
70mm (2.76")
1.4 x 2.76 =3.864"
3/16"
x
1470
70mm (2.76")
1.4 x 2.76 =3.864"
1/4"
x
1475
75mm (2.95")
1.4 x 2.95 =4.130"
1/4"
x
1540
40mm (1.57")
1.5 x 1.57 = 2.355"
3/16"
x
1567
67mm (2.64")
1.5 x 2.64 = 3.960"
1/4"
x
1630
30mm (1.18")
1.6 x 1.18 = 1.888"
1/8"
x
x
1640
40mm (1.57")
1.6 x 1.57 = 2.512"
3/16"
x
1650
50mm (1.97")
1.6 x 1.97 = 3.152"
3/16"
x
1655
55mm (2.17")
1.6 x 2.17 = 3.472"
3/16"
x
1657
57mm (2.24")
1.6 x 2.24 = 3.584"
3/16"
x
1662
62mm (2.44")
1.6 x 2.44 = 3.904"
3/16"
x
1667
67mm (2.64")
1.6 x 2.64 = 4.224"
1/4"
x
1732
32mm (1.26")
1.7 x 1.26 = 2.142"
1/8"
x
x
1735
35mm (1.38")
1.7 x 1.38 = 2.346"
1/8"
x
1740
40mm (1.57")
1.7 x 1.57 = 2.669"
3/16"
x
1740/3
40ma (1.57")
1.7 x 1.57 = 2.669"
3/16"
x
1742/3
42mm (1.65")
1.7 x 1.65 = 2.805"
3/16"
x
1745/3
45mm (1.77")
1.7 x 1.77 = 3.009"
3/16"
x
1747
47mm (1.85")
1.7 x 1.85 = 3.145"
3/16"
x
1750
50mm (1.97")
1.7 x 1.97 = 3.349"
3/16"
x
1752/3
52mm (2.05")
1.7 x 2.05 = 3.485"
3/16"
x
1755
55mm (2.17")
1.7 x 2.17 = 3.689"
3/16"
x
1760
60mm (2.36")
1.7 x 2.36 = 4.012"
3/16"
x
1860
60mm (2.36")
1.8 x 2.36 = 4.248"
3/16"
x
1930
30mm (1.18")
1.9 x 1.18 = 2.242"
1/8"
x
x
1938
38mm (1.50")
1.9 x 1.50 = 2.850"
3/16"
x
1945
45mm (1.77")
1.9 x 1.77 = 3.363"
3/16"
x
1950
50mm (1.97")
1.9 x 1.97 = 3.743"
3/16"
x
1950/3
50mm (1.97")
1.9 x 1.97 = 3.743"
3/16"
x
1955
55mm (2.17")
1.9 x 2.17 = 4.123"
3/16"
x
1957
57mm (2.24")
1.9 x 2.24 = 4.256"
3/16"
x
1967
67mm (2.64")
1.9 x 2.64 = 5.016"
1/4"
x
2035
35mm (1.38")
2.0 x 1.38 = 2.760"
3/16"
x
2045
45mm (1.77")
2.0 x 1.77 = 3.540"
3/16"
x
2047
47mm (1.85")
2.0 x 1.85 = 3.700"
3/16"
x
2050
50mm (1.97")
2.0 x 1.97 = 3.964"
3/16"
x
2055
55mm (2.17")
2.0 x 2.17 = 4.340"
3/16"
x
2060
60mm (2.36")
2.0 x 2.36 = 4.720"
3/16"
x
2137/3
37mm (1.48")
2.1 x 1.48 = 3.108"
3/16"
x
2150/3
50mm (1.97")
2.1 x 1.97 = 4.137"
3/16"
x
2160
60mm (2.36")
2.1 x 2.36 = 4.956"
3/16"
x
x
2167/3
67mm (2.64")
2.1 x 2.64 = 5.544"
1/4"
x
2250
50mm (1.97")
2.2 x 1.97 = 4.334"
3/16"
x
2260
60mm (2.36")
2.2 x 2.36 = 5.192"
3/16"
x
2267
67mm (2.64")
2.2 x 2.64 = 5.808"
1/4"
x
2352
52mm (2.05")
2.3 x 2.05 = 4.715"
3/16"
x
M447
47mm (1.85")
1.4x1.85=2.590"
3/16"
x
P735
35mm (1.38")
1.7x1.38=2.346"
1/8"
x
x
P747
47mm (1.85")
1.7x1.85=3.145"
3/16"
x
P767/3
67mm (2.64")
1.7x2.64=4.488"
1/4"
x
V937/3
37mm (1.48")
1.9x1.48=2.812"
3/16"
x
V947/3
47mm (1.85")
1.9x1.85=3.515"
3/16"
x
V955/3
55mm (2.17")
1.9x2.17=4.123"
3/16"
x
V967/3
67mm (2.64")
1.9x2.64=5.016"
1/4"
x
X427
27mm (1.07")
1.4x1.07=1.498"
1/8"
x
x
X430
30mm (1.18")
1.4x1.18=1.652"
1/8"
x
x
X430R
30mm (1.18")
1.4x1.18=1.652"
1/8"
x
x
X431
3lmm (1.22")
1.4x1.22=1.708"
1/8"
x
X432
32mm (1.26")
1.4x1.26=1.764"
1/8"
x
x
X435
35mm (1.38")
1.4x1.38=1.932"
1/8"
x
x
X437/3
37mm (1.48")
1.4x1.48=2.072"
3/16"
x
x
X438
38mm (1.50")
1.4x1.50=2.100"
3/16"
x
x
X440
40mm (1.57")
1.4x1.57=2.198"
3/16"
x
x
X440/3
40mm (1.57")
1.4x1.57=2.198"
3/16"
x
x
X442
42mm (1.65")
1.4x1.65=2.310"
3/16"
x
x
X445
45mm (1.77")
1.4x1.77=2.478"
3/16"
x
x
X447
47mm (1.85")
1.4x1.85=2.590"
3/16"
x
x
X447R
47mm (1.85")
1.4x1.85=2.590"
3/16"
x
x
X447/3
47mm (1.85")
1.4x1.85=2.590"
3/16"
x
x
X448
48mm (1.90")
1.4x1.90=2.660"
3/16"
x
x
X450
50mm (1.97")
1.4x1.97=2.758"
3/16"
x
x
X450/3
50mm (1.97")
1.4x1.97=2.758"
3/16"
x
X452
52mm (2.05")
1.4x2.05=2.870"
3/16"
x
X452/3
52mm (2.05")
1.4x2.05=2.870"
3/16"
x
X455
55mm (2.17")
1.4x2.17=3.038"
3/16"
x
X455/3
55mm (2.17")
1.4x2.17=3.038"
3/16"
x
X457
57mm (2.24")
1.4x2.24=3.136"
3/16"
x
X457R
57mm (2.24")
1.4x2.24=3.136"
3/16"
x
X457/3
57mm (2.24")
1.4x2.24=3.136"
3/16"
x
X460
60mm (2.36")
1.4x2.36=3.304"
3/16"
x
X460/3
60mm (2.36")
1.4x2.36=3.304"
3/16"
x
X462
62mm (2.44")
1.4x2.44=3.416"
3/16"
x
X465
65mm (2.56")
1.4x2.56=3.584"
3/16"
x
X465R
65mm (2.56")
1.4x2.56=3.584"
3/16"
x
X467
67mm (2.64")
1.4x2.64=3.696"
1/4"
x
X470
70mm (2.76")
1.4x2.76=3.864"
1/4"
x
X47OR
70mm (2.76")
1.4x2.76=3.864"
1/4"
x
X470/3
70mm (2.76")
1.4x2.76=3.864"
1/4"
x
X472
72mm (2.84")
1.4x2.84=3.976"
1/4"
x
X482
82mm (3.22")
1.4x3.22=4.508"
1/4"
x
X548
48mm (1.90")
1.5x1.90=2.850"
3/16"
x
X560
60mm (2.36")
1.5x2.36=3.540"
3/16"
x
X572
72mm (2.84")
1.5x2.84=4.260"
1/4"
x
X632
32mm (1.26")
1.6x1.26=2.016
1/8"
x
x
X637
37nun (1.48")
1.6x1.48=2.368"
3/16"
x
x
X640
40mm (1.57")
1.6x1.57=2.512"
3/16"
x
x
X642
42mm (1.65")
1.6x1.65=2.640"
3/16"
x
x
X645
45mm (1.77")
1.6x1.77=2.832"
3/16"
x
x
X646
46mm (1.81")
1.6x1.81=2.896"
3/16"
x
x
X646/3
46mm (1.8")
1.6x1.81=2.896"
3/16"
x
X648
48mm (1.90")
1.6x1.9=3.040"
3/16"
x
x
X665
65mm (2.56")
1.6x2.56=4.096"
3/16"
x
X665R
65mm (2.56")
1.6x2.56=4.096"
3/16"
x
X670
70mm (2.76")
1.6x2.76=4.416"
1/4"
x
Y535
35mm (1.38")
2.125"
1/8"
x
x
Y547
47mm (1.85")
2.849"
3/16"
x
Y557
57mm (2.24")
3.449"
3/16"
x
Z50
50mm (1.97")
1.6x1.97=3.152"
3/16"
x
Z55
55mm (2.17")
1.6x2.17=3.472"
3/16"
x
Z60
60mm (2.36")
1.6x2.36=3.776"
3/16"
x
1.6
1.6"
1.8x1.6=2.880"
3/16"
x
x
1.6/3
1.6"
1.8x1.6=2.880"
3/16"
x
1.8
1.8"
1.8x1.8=3.240"
3/16"
x
x
2.0
2"
1.8x2=3.600"
3/16"
x
2.0/4
2"
1.8x2=3.600"
3/16"
x
2.1/3
2.1"
1.8x2.1=3.780"
3/16"
x
2.2
2.2"
1.8x2.2=3.960"
3/16"
x
2.4
2.4"
1.8x2.4=4.320"
3/16"
x
2.4/3
2.4"
1.8x2.4=4.320"
1/4"
x
2.6
2.6"
1.8x2.6=4.680"
3/16"
x
2.8
2.8"
1.8x2.8=5.040"
3/16"
x

Graupner Carbon Fiber Propellers.
Prop
Diameter
Pitch
Fits shaft size
Carbon

Fiber





2317.40
40mm(1.57")
1.4x40=56.0mm or 2.20"
3/16"
x
2317.42
42mm(1.65")
1.4x42=58.8mm or 2.31"
3/16"
x
2317.45
45mm(1.77")
1.4x45=63.0mm or 2.48"
3/16"
x
2317.48
48mm(1.89")
1.4x48=67.0mm or 2.64"
3/16"
x
2317.51
51mm(2.01")
1.4x51=71.0mm or 2.80"
3/16"
x



Prather Propellers
Prop#
Diameter
Pitch
215
40.6mm (1.60")
2.5"
220
43.7mm (1.72")
2.6"
225
46.7mm (1.84")
2.8"
230
48.3mm (1.90")
3.0"
235
50.8mm (2.00")
3.2"
240
53.8mm (2.12")
3.3"
245
57.2mm (2.25")
3.5"
250
58.4mm (2.30")
3.6"
255
61.0mm (2.40")
3.8"
260
64.0mm (2.52")
3.9"
265
66.3mm (2.61")
4.0"
270
69.6mm (2.74")
4.2"
275
74.9mm (2.95")
4.3"
280
78.7mm (3.10")
4.5"