The manufacturing process of marine propellers has remained virtually unchanged in the last 50 years. As theboat designs evolve, the shape and style of the propellers havechanged, but they are still made the same way they were in the 1950′s.
The propeller is manufactured by sand casting technology. Sand casting is the common process tomanufacture many components. In that pattern making, forming the moldcavity, metal pouring and finishing are the main steps.
Advantages in that, many metals can be molded in different sizes, shapes and cheaper in cost. But it haspoor finish and tolerance.
Engine blocks, cylinder heads are some example part to be made. The major steps
involved in manufacturing marine propellers by sand casting method.