Tecnoseal Shaft Collar Anode - Aluminium

Tecnoseal NACA-Profile Shaft Collar Anodes — Aluminium provide sacrificial cathodic protection for marine propeller shafts from 19mm to 35mm. The range uses a compact NACA-profile shaft collar design and is offered in aluminium according to the live variants in this listing.

What Is This Shaft Anode Used For?

The two-piece collar is clamped around an exposed propeller shaft. With clean, direct metal-to-metal contact, it becomes part of the vessel’s cathodic-protection system and is consumed in preference to the shaft and other connected underwater metal components.

Key Features

• Brand: Tecnoseal
• Product category: NACA-profile shaft collar anode
• Available alloys: Aluminium
• Shaft-size range: 19mm to 35mm
• Axial width: 25mm
• Outside diameter: 55mm, 66mm, depending on size
• Mounting method: Split collar with mechanical fasteners
• Application: Marine propeller shafts with a matching measured diameter
• Manufacture: Made in Italy by Tecnoseal

How Do I Select the Correct Variant?

First match the anode’s internal diameter to the measured shaft diameter. Then confirm the available axial space, outside-diameter clearance and required alloy. Do not select a collar solely because its shaft bore is correct; the finished outside diameter must also clear the hull, stern gear and nearby fittings throughout shaft rotation.

• 00550AL: 19mm / 3/4in shaft, 25mm axial width, 55mm outside diameter, aluminium
• 00551AL: 22mm / 7/8in shaft, 25mm axial width, 55mm outside diameter, aluminium
• 00552AL: 25mm shaft, 25mm axial width, 55mm outside diameter, aluminium
• 00553AL: 25.4mm / 1in shaft, 25mm axial width, 55mm outside diameter, aluminium
• 00554AL: 28.6mm / 1 1/8in shaft, 25mm axial width, 66mm outside diameter, aluminium
• 00555AL: 30mm shaft, 25mm axial width, 66mm outside diameter, aluminium
• 00556AL: 31.8mm / 1 1/4in shaft, 25mm axial width, 66mm outside diameter, aluminium
• 00557AL: 35mm / 1 3/8in shaft, 25mm axial width, 66mm outside diameter, aluminium

Which Anode Alloy Should I Choose?

• Aluminium: generally selected for salt or brackish water and offers lower mass than an equivalent zinc casting.

Use the alloy specified by the vessel, drive or equipment manufacturer and keep the choice consistent with the existing cathodic-protection system. Water salinity, connected metals and stray-current conditions can change the correct selection.

Installation and Maintenance

Expose and clean the shaft to bright, bare metal where the anode will sit. Fit both halves squarely around the shaft and tighten the fasteners evenly in stages so the anode seats securely without rocking. Do not apply paint, grease or sealant between the anode and shaft, because direct electrical contact is required.

Inspect the anode at routine service intervals and after extended operation in a different water type. Replace it when materially consumed, cracked, loose or no longer able to clamp securely. Investigate unusually rapid or uneven wastage rather than simply fitting a larger anode.

Alloy Standards and Manufacture

Tecnoseal sacrificial anodes are manufactured in Grosseto, Tuscany. Alloy batches are checked using spectrometric analysis and produced to the applicable current US-MIL alloy specifications used by Tecnoseal for zinc, aluminium and magnesium marine anodes.

Frequently Asked Questions

• What does NACA profile mean here? It identifies the streamlined collar form used by this Tecnoseal series; it does not change the need to match the exact shaft bore and available clearance.
• Can I use a 25mm collar on a 25.4mm shaft? No. Select the exact internal diameter shown for the shaft; 25mm and 25.4mm are separate variants.
• Can different alloys be mixed on the same vessel? Do not change or mix anode alloys without checking the vessel or equipment manufacturer’s cathodic-protection specification.

Specifications