Every propeller is described by two main numbers, written as diameter × pitch: for example 14-1/2″ × 14-1/4″. Getting both right lets the engine reach its rated RPM and puts its power into the water efficiently.
Diameter
Diameter is the width of the circle the blade tips sweep. Larger diameters suit heavier boats and lower shaft speeds; smaller diameters suit lighter, faster boats and higher shaft speeds. Diameter is largely set by your engine, gearbox and the clearance under the hull.
Pitch
Pitch is the distance, in inches, a propeller would move forward in one full revolution if it were moving through a solid, with no slip. A 19-pitch prop would travel 19 inches per turn. In practice:
- Higher pitch lowers engine RPM at full throttle and can raise top speed, if the engine has the power to turn it.
- Lower pitch raises engine RPM and improves acceleration and pulling power, at the cost of top speed.
- As a rule of thumb, each inch of pitch changes full-throttle engine speed by roughly 150-200 RPM.
The goal is for the engine to reach the top of the full-throttle RPM range in its owner’s manual with a normal load. If it over-revs, go up in pitch; if it cannot reach the range, go down.
Three or four blades?
Three-blade props are the common all-rounder. Four-blade props usually give a stronger hole shot, better grip in rough water and smoother running, with a small loss of top speed.
Bronze, nibral or stainless
Bronze is the traditional material for inboard propellers. Nibral (nickel-aluminum-bronze) is a stronger, more corrosion-resistant alloy used on larger and commercial boats. Stainless steel is common on high-performance outboards. Compare them in stainless steel vs aluminum props.
Rotation, bore and cup
Propellers turn either right-hand (RH) or left-hand (LH); twin-engine boats usually run one of each. Inboard propellers must also match the shaft’s bore size and taper, and some props have a cupped trailing edge that adds grip, similar to adding a little pitch. Copy these figures from your current propeller. They are usually stamped on the hub.
Propellers in stock
- ACME 1235 14-1/2" x 14-1/4" x .105 cup with 1-1/8" bore LH boat prop: $832.49
- Michigan Wheel 17 inch Dyna-Jet 3 Blade Bronze Prop DJ3B17B: $1,060.49
- Yamaha – M/T Series V MAX SHO Stainless Steel Propeller – 3 Blade – 15-1/8" x 25 Pitch – RH Rotation – 6CB-45972-11-00: $1,088.67
- Michigan Wheel 18 inch DynaQuad 4 Blade Bronze Prop DQ4B18B: $1,318.49
- Michigan Wheel 19 inch DynaQuad 4 Blade Bronze Prop DQ4B19B: $1,489.49
- Michigan Wheel 20 inch DynaQuad 4 Blade Bronze Prop DQ4B20B: $1,630.49
- Michigan Wheel 22 inch DynaQuad 4 Blade Bronze Prop DQ4B22B: $2,065.49
- Michigan Wheel 18 inch DQX 4 Blade Nibral Prop DQX4B18N: $2,100.49
- Michigan Wheel 24 inch DynaQuad 4 Blade Bronze Prop DQ4B24B: $2,528.49
- Michigan Wheel 26 inch DynaQuad 4 Blade Bronze Prop DQ4B26B: $3,214.49
- Michigan Wheel 44 inch MY-T4 4 Blade Bronze Prop MYT4B44B: $16,804.80
- Michigan Wheel 42 inch MY-T4 4 Blade Nibral Prop MYT4B42N: $16,943.40
- Michigan Wheel 44 inch MY-T4 4 Blade Nibral Prop MYT4B44N: $18,806.40
See all boat propellers and Michigan Wheel propellers. Check your current prop with our prop slip calculator. Send us the numbers stamped on your current prop and we will confirm the replacement. Shipping is a flat $80.00 per order with 15-day free returns.