The Marine Propeller Hub is the central structural component of a marine propulsion system, connecting the propeller blades to the propulsion shaft and transmitting engine torque to generate thrust. Operating in harsh seawater environments, the hub must resist corrosion, cavitation erosion, and galvanic attack while maintaining high mechanical strength and dimensional precision for blade mounting.

Ningbo Ruican manufactures this hub using precision Investment Casting of C95800 nickel-aluminum bronze (NAB), a material renowned for its exceptional seawater corrosion resistance, high yield strength, and anti-biofouling properties. Our CNC MACHINING ensures precise blade root slots, taper bore, and keyway dimensions to exacting marine standards.

Material Specifications

Parameter	Specification
Material	C95800 (NiAl Bronze, ASTM B148)
Tensile Strength	≥ 655 MPa
Yield Strength	≥ 250 MPa
Elongation	≥ 10%
Hardness	150–200 HBW
Composition	Cu 79%, Al 9%, Ni 4.5%, Fe 4%, Mn 1%, Si 0.1%
Corrosion Resistance	Excellent in seawater (per ASTM G48)

Casting Specifications

Parameter	Specification
Casting Process	Silica sol investment casting
Dimensional Tolerance	ISO 8062 CT5–CT6
Surface Roughness	Ra 3.2–6.3 μm (as-cast); Ra 1.6 μm (machined)
Weight Range	5–150 kg
Wall Thickness	8–40 mm
Casting Defect Level	Level 2 per ASTM E446

CNC Machining Parameters

Parameter	Specification
Taper Bore Tolerance	±0.015 mm (matched to shaft)
Keyway Width	H7 tolerance
Blade Root Slot	±0.02 mm positional tolerance
Surface Finish (bore)	Ra 0.8 μm (ground)
Threaded Holes	Class 6H per ISO 965
Runout (taper bore to OD)	≤ 0.05 mm