Tohatsu is a manufacturer of aftermarket boat props designed to be installed on outboard motors. The standard sizes of Tohatsu Boat Props vary from a diameter of a few inches to much larger propellers that measure almost a foot across. The different sizes of propellers from Tohatsu also differ in pitch, a term that refers to the distance that a full revolution of the propeller will move the boat forward.
Materials Used in Construction- majority of Tohatsu boat props are made of aluminum, but the company also makes some that use stainless steel as their base material. The latter propellers generally fit on motors that are rated at 25 horsepower and above. Aluminum propellers are more lightweight for their surface area and can have additional advantages. Some boating enthusiasts report that some aluminum propellers produce a quieter ride than do stainless steel models.
Pitch and Load Considerations- Pitch has more implications than simply the distance a boat will move forward as the propeller spins. Propeller pitch is also a major factor in determining what the top speed of a boat will be as well as how fast that boat can accelerate to reach its top speed.
Another important thing to consider is the load rating of a propeller. A light load is considered to be from 100 to 500 pounds. Propellers that can handle boats and contents weighing between 500 and 1,500 pounds are classed in the medium load rating. A heavy load varies from 1,500 pounds to 3,000 pounds.
When it comes to the sport and science of boating, “rake” definitely does not refer to a garden implement or the hero of a Regency novel. Instead, rake in Force Boat Props is a precise mathematical measurement related to the blades of the propeller.
In Force Propellers and other brands of props, “rake” refers to the amount of slant the blades exhibit compared to the hub, or central spoke, of the propeller. Each blade attaches to the hub, but they may slant in one of several directions: forward, backwards, or vertically with no discernible slant at all. A blade that appears to lean backwards is said to have “aft rake,” while one that leans forward is described as having “forward rake” or sometimes “negative rake.” Perfectly vertical blades that form a 90-degree angle with the hub are said to have no rake.
In Force props, the type and degree of rake will influence how much water flows through the blades of the propeller. This in turn will affect the performance of watercraft as they are piloted on lakes, rivers, and oceans.
Propellers having aft rake can be useful because they help to lift the bow of the watercraft. This can help the boat move at faster speeds because less of it will be in the water subject to the drag of friction. Forward rake has the opposite effect and helps to keep the bow of the boat in better contact with the water, which can be desirable when speed is not an issue.