Tecnoseal 873412 Volvo Penta Propeller Nut Anode for Ø30 mm Shaft

Tecnoseal WE728 / WE728MG Volvo Penta 873412 Propeller Nut Anode for Ø30 mm Shaft – Zinc / Magnesium

The Tecnoseal WE728 and WE728MG are sacrificial propeller nut anodes compatible with Volvo Penta fixed-pitch bronze propeller installations. Designed for 30 mm propeller shafts, these anodes correspond to Volvo Penta original part number 873412 and are available in zinc and magnesium versions.

Both variants feature a tapered, cone-shaped body with a central threaded connection. The manufacturer specifies a 20 × 1.5 mm thread, an overall height of 71 mm, an internal height measurement of 32 mm and an outside diameter of 37 mm.

The zinc and magnesium versions share the same dimensions and mounting specification, allowing selection of the appropriate sacrificial anode material for the vessel's operating environment.

Available Variants

• Tecnoseal WE728 – Zinc: Propeller nut anode for Volvo Penta fixed-pitch bronze propellers, Ø30 mm shaft, 20 × 1.5 mm thread. Weight: 0.29 kg (0.64 lbs).
• Tecnoseal WE728MG – Magnesium: Propeller nut anode with the same dimensions and thread specification. Weight: 0.08 kg (0.18 lbs).

Technical Specifications

Volvo Penta Propeller Compatibility

These Tecnoseal nut anodes are designed for Volvo Penta fixed-pitch bronze propellers installed on 30 mm propeller shafts. The manufacturer identifies 873412 as the corresponding original part number.

Both variants feature the same tapered external profile and 20 × 1.5 mm threaded mounting connection. Before ordering, check the original component and confirm the shaft diameter, thread size and installation geometry.

Construction and Dimensions

The propeller nut anode features a tapered cylindrical body with an internal threaded mounting connection. Its shape is designed to suit the corresponding Volvo Penta fixed-pitch propeller installation.

• Shaft size: Ø30 mm.
• Overall height (h): 71 mm (2.80 in).
• Height (h1): 32 mm (1.26 in).
• Outside diameter (Ø): 37 mm (1.46 in).
• Internal thread (m): 20 × 1.5 mm.

These measurements apply to both zinc and magnesium versions. The main differences between the variants are their sacrificial anode material and weight.

Zinc and Magnesium Anode Materials

Zinc (WE728) is commonly used for sacrificial corrosion protection in saltwater environments. When properly installed with electrical continuity, the zinc corrodes preferentially to help protect connected underwater metallic components.

Magnesium (WE728MG) is generally selected for freshwater corrosion protection systems because of its higher electrochemical activity. Its suitability depends on the vessel's operating conditions and the requirements of the corrosion protection arrangement.

Choose the appropriate material according to the operating water environment and the equipment manufacturer's recommendations.

Inspection and Replacement

Inspect the propeller nut anode during routine propeller and shaft maintenance. Replace it when the sacrificial material becomes significantly depleted, damaged or no longer securely attached.

During replacement, confirm the 30 mm shaft specification and 20 × 1.5 mm thread, inspect the mounting connection and follow the relevant propeller installation instructions.

Scope of Supply

1 × Tecnoseal Volvo Penta Compatible Propeller Nut Anode in the selected material:

• WE728 – Zinc; or
• WE728MG – Magnesium.