How is a Mercury propeller made?
It all starts with a propeller mold. Cast in a specially designed hot wax using a 5000 year old technique. Reinforced with two layers of ceramic during an application process that takes two full days. The mold is then steam heated in an autoclave at 163°C and a pressure of 100 PSI. Finally, it is placed in a baking oven at over 1093°C, a temperature that requires workers to wear protective aluminized clothing. After curing, now shock-resistant, the mold is ready. Liquid stainless steel, heated to 1650°C, is then poured into the mold, at a rate of 23 kg per mold. The newly cast propellers cool on carts for about an hour. Machines similar to jackhammers, abrasive saws and sanders then remove any ceramic residue and traces of oxidation. Operators grind and prepare the propellers for specific applications. And sharpeners thin the leading edges of the blades and sand the other areas.
Then comes the surface finish. Two hours in a rotary table blast machine eliminates roughness and gives Bravo Three propellers or propellers for multidirectional thrusters the matt finish that characterizes them. The other propellers go through a browning process that gives them a high gloss finish.
The final step is to equip the propellers with the Performance Vent System. They are now ready to be installed.
Stainless steel or aluminium?
The propeller is the link that transmits engine power to the water. It must therefore deform to a minimum. For this purpose, propeller manufacturers offer stainless steel propellers. Stainless steel has the advantage of not being afraid of seawater and of being very inflexible. But it is also an expensive material to use. For powers below 100 hp, it is considered that aluminium (cheaper) does not deform sufficiently and can act as a good propeller.
However, because Mercury could not find an aluminium alloy good enough for its propellers, it invented one: Mercalloy aluminium. Exclusively patented, the Mercalloy allows more resistant parts to be cast. And therefore thinner blades that create less drag. This Mercalloy aluminum designed for the casting process produces high quality, non-porous castings that offer increased strength and ductility, i.e. the ability to deform without breaking.
As with aluminium, Mercury uses exclusive and patented stainless steel for the design and creation of propellers that ensure lower performance and consumption. For example, Alloy X7 which is 30% stronger and 4 times more durable than conventional stainless steel. This alloy simply makes it possible to design propellers that are not possible with conventional stainless steel. This alloy is found, for example, on the famous 3-blade Enertia propeller, but also on the Fury and Fury 4s and the SpitFire X7.
Mercury propellers for all outboards
With its adaptable Flo-Torq hub, Mercury allows its propellers to be installed on all outboard engines on the market. An adapter exists for each engine brand. Thus the very wide range of propellers is available for all boaters.
Mercury offers 3 ranges of propellers:
- Accounting
- Elite, the most efficient and expensive range.
- sportboat
Comp Series
Known in the market as the most efficient propellers in terms of acceleration, top speed and fuel economy. The famous Enertia mounted on many Mercury Veradoes and the Enertia Eco, which significantly reduces fuel consumption at cruising speed, are part of this range. The other models presented in this series are the Fury, Revolution 4 and Bravo 1.
Elite Series
These propellers are the strongest and most efficient in their class. They are also the most popular.
Sport Series
Perfect balance between performance and price. Ideal models for boaters who want to improve their boat's performance. The world's best-selling Black Max aluminium propellers are part of this range. The other models presented in this series are the Mirage Plus, Terophy Sport, HighFive, Laser 2, Vengeance and Bravo 2.
A selector to find the right propeller
To help you pre-select your propeller, Mercury Marine has set up a Prop Selector on its website. This selector allows you to choose in 5 steps the ideal propeller for your type of boat and the use you want to have.
