Marine anodes, including zinc, aluminum, and magnesium anodes, are sacrificial metal components used to protect the hull and underwater metal parts of boats and yachts from galvanic corrosion. By corroding preferentially, the anodes help protect more valuable submerged components such as hull fittings, propeller shafts, rudders, trim tabs, and other bonded metal parts.
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1-2 weeks delivery time Tecnoseal magnesium Limited Clearance shaft collar sacrificial anodes for shaft installations where a compact collar profile is required. The range includes fourteen models for metric and imperial shaft sizes from 19 mm / 3/4" up to 50 mm / 1-1/2", with weights from 0.05 to 0.15 kg. Available versions feature heights from 18 to 25 mm, overall diameters from Ø61 to Ø85 mm and internal shaft diameters from 19 to 50 mm. Metric versions are available for 20, 25, 30, 35, 40, 45, 48 and 50 mm shafts, together with 3/4", 7/8", 1", 1-1/8", 1-1/4" and 1-1/2" imperial configurations. Select the required model according to shaft size, overall diameter, collar height and weight.
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$ 19.05
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1-2 weeks delivery time Tecnoseal magnesium Standard Type shaft sacrificial anodes for marine shaft installations, available for metric and imperial shaft sizes from 19 mm / 3/4" up to 80 mm. The range includes models with 2 fastening holes for shaft sizes from 19 mm through 2" / 50.8 mm, and larger models with 4 fastening holes for shafts from 55 to 80 mm. Depending on the model, anode height ranges from 56 to 110 mm, overall diameter from Ø58 to Ø128 mm and magnesium anode weight from 0.09 to 0.69 kg. Bolts and nuts are available on request. Select the required Tecnoseal model according to shaft diameter, overall dimensions, fastening-hole configuration and weight.
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$ 27.12
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1-2 weeks delivery time Tecnoseal magnesium UK Type shaft sacrificial anodes for marine shaft installations, available in six metric and imperial shaft configurations from 19 mm / 3/4" up to 30 mm. All models have a height of 65 mm and an overall outside diameter of Ø56 mm, with shaft openings from 19 to 30 mm. The range includes 3/4", 7/8", 1" and 1-1/8" imperial versions together with 25 mm and 30 mm metric sizes, with listed magnesium anode weights from 0.01 to 0.18 kg. Bolts and nuts are not included. Select the required model according to shaft size, Ø1 opening and weight.
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$ 63.03
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1-2 weeks delivery time Tecnoseal magnesium USA Type shaft sacrificial anodes for marine shaft installations, available for shaft sizes from 19 mm / 3/4" up to 60 mm and including both metric and imperial configurations. The range includes compact 2-fastening-hole models from 00500USAMG through 00514USAMG, plus the larger 00517USAMG version with 4 fastening holes. Depending on the model, anode height ranges from 51 to 102 mm, overall diameter from Ø54 to Ø107 mm and magnesium anode weight from 0.09 to 0.65 kg. Bolts and nuts are available on request. Select the required model according to shaft size, overall dimensions, fastening configuration and weight.
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$ 27.12
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1-2 weeks delivery time Tecnoseal zinc NACA-profile shaft collar sacrificial anodes, available in nine sizes for shafts from 19 to 35 mm, including metric and imperial shaft configurations. All models have a height of 25 mm, with outside diameters of Ø55 or Ø66 mm depending on size. The range covers Ø1 shaft openings from 19 to 35 mm and zinc anode weights from 0.22 to 0.32 kg. Select the required model according to shaft diameter, outside diameter and weight.
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$ 22.18
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1-2 weeks delivery time Tecnoseal zinc shaft collar sacrificial anodes available in Limited Clearance, Slim, Medium and Large Size configurations for shaft diameters from 19 mm / 3/4" up to 360 mm. The range includes metric and imperial shaft sizes, with collar heights from 18 to 60 mm, overall diameters from Ø61 to Ø511 mm and weights from 0.21 to 49.40 kg. Available models include compact collars for 19–50 mm shafts, medium-size versions for shafts up to 95 mm and large collars for shaft diameters from 100 to 360 mm. Select the required Tecnoseal model according to shaft diameter, overall collar diameter, height and weight.
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$ 16.59
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1-2 weeks delivery time Tecnoseal zinc Standard Type shaft sacrificial anodes for marine shaft installations, available for shaft sizes from 19 mm / 3/4" up to 90 mm and including both metric and imperial configurations. The range includes models with 2 fastening holes for shaft sizes from 19 mm through 2" / 50.8 mm, and larger models with 4 fastening holes for shafts from 55 to 90 mm. Depending on the model, anode height ranges from 56 to 113 mm, overall diameter from Ø58 to Ø137 mm and weight from 0.41 to 3.65 kg. Bolts and nuts are available on request. Select the required model according to shaft diameter, overall dimensions, fastening-hole configuration and weight.
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$ 30.72
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1-2 weeks delivery time Tecnoseal zinc Barrel Type shaft sacrificial anodes for marine shaft installations, manufactured with 4 fastening holes. The range includes nine models for shaft diameters from 95 to 130 mm, with anode weights from 5.10 to 15.20 kg. Depending on the model, heights range from 114 to 156 mm and overall diameters from Ø142 to Ø180 mm. Bolts and nuts are available on request. Select the required Tecnoseal model according to shaft diameter, anode height, overall diameter and weight.
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$ 297.96
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1-2 weeks delivery time Tecnoseal zinc Light Type shaft sacrificial anodes for marine shaft installations, available in five metric and imperial shaft configurations from 19 mm / 3/4" to 28 mm. All models feature 2 fastening holes, a 40 mm height and Ø50 mm overall diameter, with shaft openings from 19 to 28 mm and weights from 0.22 to 0.31 kg. The range includes Tecnoseal 00500L for 19 mm / 3/4" shafts, 00501L for 7/8" shafts, 00502L for 25 mm shafts, 00503L for 1" shafts and 00504L for 28 mm shafts. Bolts and nuts are available on request. Select the required model according to shaft diameter and anode weight.
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$ 29.17
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1-2 weeks delivery time Tecnoseal zinc UK Type shaft sacrificial anodes for marine shaft installations, available in metric and imperial shaft configurations from 19 mm / 3/4" up to 50 mm. The range includes thirteen models with shaft openings from 19 to 50 mm, heights from 65 to 100 mm, overall diameters from Ø56 to Ø85 mm and weights from 0.56 to 2.47 kg. Available imperial configurations include 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-1/2" and 1-3/4". Bolts and nuts are not included. Select the required Tecnoseal model according to shaft size, height, overall diameter and weight.
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$ 71.93
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1-2 weeks delivery time Tecnoseal zinc USA Type shaft sacrificial anodes for marine shaft installations, available for shaft sizes from 19 mm / 3/4" up to 6-1/2" / 165 mm. The range includes metric and imperial shaft configurations with 2 fastening holes on models up to 00514USA and 4 fastening holes on larger models from 00516USA onward. Depending on model, anode height ranges from 51 to 102 mm, overall diameter from Ø54 to Ø209 mm and weight from 0.36 to 6.35 kg. USA reference designations include X-1 to X-22 and D-series references for selected metric sizes. Bolts and nuts are available on request. Select the required version according to shaft size, Ø1 opening, overall dimensions, fastening-hole configuration and weight.
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$ 37.59
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1-2 weeks delivery time Tecnoseal aluminium Radice conical propeller sacrificial anodes for fixed pitch propeller installations, supplied as replacement anodes only. The range includes ten models for shaft sizes from Ø22–25 mm up to Ø110 mm, with weights from 0.05 to 3.00 kg. Available versions range from 39 to 134 mm in height and from Ø33 to Ø160 mm in overall diameter, with individual Ø1, Ø2 and Ø3 dimensions for replacement matching. Select the required Tecnoseal model according to shaft size, anode dimensions and weight.
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$ 5.43
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1-2 weeks delivery time Tecnoseal aluminium Radice conical propeller sacrificial anodes for fixed pitch propeller installations, supplied complete with a brass plug. The range includes nine standard brass plug models and selected non-standard configurations for shaft sizes from Ø22–25 mm up to Ø70/100 mm. Available versions range from 20 to 46 mm in h dimension, 18 to 46 mm in h1 dimension and from Ø37 to Ø100 mm in overall diameter, with weights from 0.11 to 4.52 kg. Standard models use the corresponding Radice brass plug thread, while the non-standard versions include Tecnoseal 00410-2AL with 18x1.5 thread, 00413-1AL with 26x2 thread and 00414-2AL with 30x2 thread. Select the required version according to shaft size, plug type, thread size, dimensions and weight.
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$ 57.86
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1-2 weeks delivery time Tecnoseal aluminium Radice hexagonal-type propeller sacrificial anodes for fixed pitch propeller installations, supplied as replacement anodes only. The range includes nine models for shaft sizes from Ø22–25 mm up to Ø70/100 mm, with weights from 0.05 to 1.01 kg. Available versions range from 39 to 98 mm in height and from Ø33 to Ø97 mm in overall diameter, with individual c, Ø1 and Ø2 dimensions for replacement matching. Select the required model according to shaft size, anode dimensions and weight.
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$ 6.74
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1-2 weeks delivery time Tecnoseal magnesium Radice conical propeller sacrificial anodes, supplied as replacement anodes only. The range includes ten models for shaft sizes from Ø22–25 mm up to Ø110 mm, with weights from 0.04 to 1.93 kg. Available versions range from 39 to 134 mm in height and from Ø33 to Ø160 mm in overall diameter, with individual Ø1, Ø2 and Ø3 dimensions for replacement matching. Select the required Tecnoseal model according to shaft size, anode dimensions and weight.
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$ 12.95
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1-2 weeks delivery time Tecnoseal magnesium Radice hexagonal-type propeller sacrificial anodes for fixed pitch propeller installations, supplied as replacement anodes only. The range includes nine models for shaft sizes from Ø22–25 mm up to Ø70/100 mm, with weights from 0.03 to 0.65 kg. Available versions range from 39 to 98 mm in height and from Ø33 to Ø97 mm in overall diameter, with individual c, Ø1 and Ø2 dimensions for replacement matching. Select the required model according to shaft size, anode dimensions and weight.
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$ 14.80
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1-2 weeks delivery time Tecnoseal magnesium Radice hexagonal-type propeller sacrificial anodes for fixed pitch propeller installations, supplied complete with a standard brass plug. The range includes nine models for shaft sizes from Ø22–25 mm up to Ø70/100 mm, with weights from 0.21 to 4.08 kg. Available versions range from 19 to 45 mm in h dimension, 18 to 54 mm in h1 dimension and from Ø37 to Ø100 mm in overall diameter. Standard brass plug thread sizes range from 16x1.5 to 50x3 depending on model. Select the required version according to shaft size, thread size, dimensions and weight.
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$ 200.84
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1-2 weeks delivery time Tecnoseal zinc Radice conical propeller sacrificial anodes for fixed pitch propeller installations, supplied as replacement anodes only. The range includes ten models for shaft sizes from Ø22–25 mm up to Ø110 mm, with weights from 0.14 to 7.65 kg. Available versions cover heights from 39 to 134 mm and overall diameters from Ø33 to Ø160 mm, with individual Ø1, Ø2 and Ø3 dimensions for replacement matching. Select the required Tecnoseal model according to shaft size, anode dimensions and weight.
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$ 11.95
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1-2 weeks delivery time Tecnoseal zinc Radice conical propeller sacrificial anodes for fixed pitch propeller installations, supplied complete with a brass plug. The range includes standard brass plug versions and non-standard configurations for shaft sizes from Ø22–25 mm up to Ø70/100 mm. Available models cover overall diameters from Ø37 to Ø100 mm, h dimensions from 20 to 46 mm and h1 dimensions from 18 to 54 mm, with weights from 0.27 to 7.15 kg. Standard and non-standard versions are differentiated by the m specification, including multiple thread sizes, left-hand thread versions and Ø8, Ø10 or Ø12 hole configurations. Select the required model according to shaft size, plug thread or hole specification, dimensions and weight.
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$ 64.40
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1-2 weeks delivery time Tecnoseal zinc Radice hexagonal-type propeller sacrificial anodes for fixed pitch propeller installations, supplied as replacement anodes only. The range includes nine models for shaft sizes from Ø22–25 mm up to Ø70/100 mm, with weights from 0.12 to 2.58 kg. Available versions range from 39 to 98 mm in height and from Ø33 to Ø97 mm in overall diameter, with individual c, Ø1 and Ø2 dimensions for replacement matching. Select the required model according to shaft size, anode dimensions and weight.
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$ 12.81
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How do Aluminum, Zinc, and Magnesium Anodes differ in protecting a boat?
Aluminum, zinc, and magnesium anodes all provide cathodic protection by acting as sacrificial metals, but their effectiveness depends on the water type and their electrochemical potential. Zinc anodes are traditionally used in saltwater and provide reliable protection in high-salinity environments. Aluminum anodes are more electrochemically active than zinc and offer a higher protective capacity for their weight, making them suitable for saltwater and brackish water and, with the correct alloy, many freshwater applications. Magnesium is the most active of the three materials and is primarily intended for freshwater, where its higher driving voltage provides effective protection in low-conductivity conditions. Magnesium anodes should generally not be used in saltwater or brackish water, as they may provide excessive protection and be consumed too rapidly.
Why is anode placement on the hull plate important for effective corrosion protection?
Correct anode placement is essential because sacrificial anodes must be electrically connected to the metal they protect and positioned where protective current can reach exposed underwater surfaces effectively. On metal hulls, anodes should be distributed around areas that are most susceptible to galvanic corrosion, including the hull plating, rudder, propeller shaft, stern gear, and other submerged metal components. Poorly positioned, undersized, or electrically isolated anodes may leave parts of the structure insufficiently protected. Proper distribution helps maintain a more uniform protective potential across the underwater metalwork and reduces the risk of localized corrosion.