Black Plastic Coated Neodymium Ring Magnet – 77mm (OD) X 8mm (ID) X 17mm (H) I 6 Multi-Poled

This high-strength Neodymium Ring Magnet (N45) features an outer diameter of 77mm, an inner diameter of 8mm, and a height of 17mm. It is axially magnetised with a 6-multipole configuration, enhancing its efficiency in specialised applications. The black plastic coating provides durability, corrosion resistance, and a smooth surface for easy handling.

Ideal for Prawn Farming & Artemia Separation

This neodymium ring magnet is widely used in prawn farms to efficiently separate Artemia (brine shrimp) from their casings. Its strong multi-poled magnetic field attracts and retains non-nutritious cyst shells, ensuring a cleaner and higher-quality feed for aquatic species.

Designed for harsh marine environments, the protective plastic coating enhances longevity by shielding the magnet from moisture and chemical exposure. Whether used in hatcheries or large-scale aquaculture, this magnet provides a reliable, non-invasive solution for improving feed quality and reducing waste.

Rough Pull Force Estimate

For a single-pole, axially magnetised neodymium ring magnet of similar size (without multi-pole magnetisation), the pull force would typically range from 80–120 kg when in direct contact with a thick ferrous surface.

However, because this magnet is multi-pole, the force is distributed across multiple poles instead of being concentrated at one surface. This generally reduces the direct pull force but improves lateral gripping strength and efficiency in applications like Artemia separation.

Estimated Pull Force:

• Direct contact with a thick steel plate: ~50–80 kg (adjusted for multi-pole effect).
• Pull force at a small air gap (1-2mm): ~30–50 kg (plastic coating increases the gap).
• Shear force (lateral strength for holding/sliding applications): Potentially higher due to multiple poles improving grip.