We make long Neodymium bar magnets for linear motors, magnetic separators, and industrial holding systems. Long magnets are difficult to manufacture. They must stay strong and keep an even magnetic field throughout their length. We offer two options: – Solid one-piece bars for maximum performance – Glued sections for lower cost on longer sizes We can make bars over 200mm long. Most standard manufacturing methods have length limits, but our bonding process overcomes this. The “Long Magnet” Solution 1. Monolithic (Solid Single-Piece) – Max Length: Typically up to 150mm – 200mm (depending on cross-section). – Best For: High-speed motors or applications where structural rigidity is paramount. – Feature: Seamless finish with no internal bond lines. 2. Composite / Spliced Assemblies – Max Length: Virtually unlimited (Commonly supplied over 300mm). – Construction: Multiple magnet segments are precision-ground and bonded using industrial-grade high-strength epoxy. – Best For: Magnetic separators, filter rods, and door sensors. Feature: We use a proprietary bonding process that minimizes the “magnetic dip” at the joint Ensuring a near-continuous magnetic field. Technical Specifications Material Grades: N35–N52, M, H, SH, UH, EH, AH (Temp ratings up to 230°C). Length (L): Custom over 300mm (via splicing) Cross-Section: Square or Rectangular (e.g., 10x10mm, 50x20mm). Tolerances Length: ±0.1mm (Standard). Width/Thickness: ±0.05mm. Straightness Strict control over camber/bowing for linear motor tracks. Critical Engineering Controls 1. Geometric Tolerance: Straightness & Flatness Long, thin magnets are prone to warping (the “banana effect”) during production. Our Standard: – We perform flatness checks on long bars during production and before packing. – Ensure they sit flush against your mounting surface. Precision Grinding: – For linear motor tracks, we can offer precision grinding. – Ensure parallelism between the top and bottom faces. 2. Handling Brittleness The aspect ratio (Length vs. Thickness) makes long magnets fragile. Recommendation: If the Length-to-Thickness ratio is high (e.g., a magnet 100mm long but 2mm thick), we recommend using a backing plate. Or, choose a spliced option to reduce the risk of snapping during installation. Magnetization Directions Through Thickness: – The standard orientation. – Used for clamping, separation grates, and holding. Axial (Through Length): – Caution: Magnetizing a very long bar through the length is difficult due to saturation limits. – Please consult us for feasibility on bars longer than 100mm. Multi-Pole: – We can provide linear multi-pole magnetization (N-S-N-S) on a single face – Ideal for linear actuators and sensors. Surface Treatments Ni-Cu-Ni (Nickel): Standard protection. Epoxy: – Recommended for spliced magnets – The black epoxy coating helps seal and hide the bond lines, creating a unified appearance. Stainless Steel Sheathing: – For food-grade separation applications, we can encase the magnets in 304/316 Stainless Steel tubes. Logistics & Safety Packaging Long magnets break during shipping if not properly packed. Shipping long, powerful magnets requires additional attention: Rigid Support: – All long bars are strapped to rigid timber or heavy-duty plastic boards. – Prevent flexing and snapping during transport. Spacers: – Thick non-magnetic spacers are used to separate the bars – Ensure you can remove them safely without them slamming together. Iron Shielding: – Full magnetic shielding to comply with IATA air cargo regulations. Ordering Guide: What to Specify 1). Dimensions: Length x Width x Thickness. 2). Continuous vs. Spliced: Do you accept glued segments (cheaper/longer) or do you need a solid piece? 3). Grade: Standard or High Temp? 4). Application: – For example, “Linear Motor” requires high straightness – “Filter Rod” implies stainless steel casing.