Propeller diameter is the distance across an imaginary circle that a spinning propeller makes. It can be easily determined by measuring the distance from the center of the hub to the tip of one of the blades and multiplying that number by 2. On a four blade propeller you can directly measure the diameter from tip to tip on opposing blades.
Diameter is the first number on the size of a propeller: a 14”X19” is a 14 inch diameter propeller with a 19” pitch blade. Many propeller manufacturers change diameter as the pitch increases or decreases: as an example, a typical size range for a Mercury Alpha One I/O would be 14-1/2”x19”, 15”x17” or 15-1/2”x15”. As the pitch decreases, the diameter often increases.
Diameters between different propeller manufacturers may vary slightly. On Turning Point propellers, this is due to more aggressively engineered designs on blade geometries. As an example, Turning Point offers a 14-1/4” diameter propeller for most V6 outboard and I/O applications. Other manufacturers propellers may range from 13-1/2” up to 16” for this same engine. These diameter variances do not affect your performance as much as the pitch and overall design. In other words, you do not need to match the diameter of your current propeller when you are purchasing a new one from Turning Point. Larger diameter propellers - 15" or 16" diameter - are designed for larger boat applications - 23 ft +. These larger boats need more blade area to carry the hull properly and push more water.
Consult your Turning Point Propeller dealer to learn about how our propellers will improve the performance of your boat. Turning Point has been engineering, manufacturing and marketing high-performance, pleasure craft aluminum and stainless steel propellers for over 15 years. Our innovative products are available worldwide through an extensive family of dealers and retail outlets, which can be found on the "Find a Dealer" section of our website www.turningpointpropellers.com
Contact Turning Point Propellers at 847-437-6800 or at sales@turningpointpropellers.com
What is Propeller Diameter?
By: TP. Engineering
Turning Point Propellers, Inc.Published: 2012-10-12
