We make half-ring and C-shaped Neodymium magnets for motors, magnetic couplings, and sensors. These are also called split rings or 180° arc segments. You use them when a standard full ring won’t fit – like when you need to clamp around a shaft. We can make simple pairs or more complex C-shaped designs. We manufacture to tight tolerances. This means the pieces fit together with small gaps, so the magnet works at full strength. The “Matched Pair” Service Perfect Mating & Poling: When purchasing Half Rings to form a full circle, polarity is critical. We supply these magnets in Matched Pairs: A/B Pairing: – We ensure that one half is North-oriented and the other is South-oriented at the interface – Ensuring they attract/clamp correctly around your assembly. Gap Control: – We verify the dimensional consistency between pairs to ensure that when the two halves meet. – Make sure they form a perfect circle with minimal gap variance. Magnetization Directions This is the most confusing part for curved magnets. You must clarify the requirement. How the magnetic field interacts with the curve is vital for your application. We support: Radial Magnetization: – The magnetic field radiates from the center (Inner Diameter to Outer Diameter). – Ideal for high-performance motors. Diametric Magnetization: – The field runs straight through the diameter of the ring (Parallel lines). – Common for sensor magnets. Axial Magnetization: – The field runs through the length/height of the cylinder. – Common for clamping/holding. Halbach Array Segments: – We can supply arc segments with varying magnetization angles to create Halbach arrays (concentrating the field on one side). Technical Specifications Grades: – N35–N52 – Plus High-Temp Series (M, H, SH, UH, EH, AH up to 230°C). Angular Tolerance Standard: – 180° (Half Ring). – Custom arcs (e.g., 120°, 90°, 60°) also available. Dimensions ID: – Inner Diameter – OD: Outer Diameter – H: Height/Length. Size Capability: – Micro-rings (ID < 3mm) – Large Industrial Rings (OD > 150mm). Coatings: – Ni-Cu-Ni, Zinc, Epoxy, Parylene (for precision fit), Everlube. Geometric Considerations 1. Chamfers & Edges Half rings have sharp edges where the curved surface meets the flat face. – Standard: We apply a chamfer to all edges to prevent chipping during the “snap-together” assembly process. – Custom: We can supply specific chamfer dimensions or double-countersunk holes if the half-ring needs to be bolted onto a carrier. 2. Tolerance Stack-up – Outer Diameter (OD) Fit: If the magnet goes inside a housing (tube), we usually hold a negative tolerance (e.g., 0 / -0.05mm). – Inner Diameter (ID) Fit: If the magnet clamps around a shaft, we usually hold a positive tolerance (e.g., 0.05 / -0mm). Please inform us of your assembly method (Glued vs. Press-Fit). So, we can suggest the correct tolerance class. Applications Rotary Encoders: Precision magnetized half-rings for position sensing. Retrofit Motors: Clamping magnets onto a rotor shaft without disassembling the motor. Magnetic Bearings & Couplings: Non-contact torque transfer. Holding Systems: C-clips for securing pipes or cables. Ordering Guide: What We Need to Quote To provide the fastest and most accurate quotation, please provide: 1). Dimensions: OD, ID, Length/Height. 2). Angle: Is it exactly 180° (Half Ring) or a different arc segment? 3). Magnetization: Radial, Diametric, or Axial? 4). Grade: Standard or High Temperature? 5). Assembly Plan: – Will you use them individually or as a pair? – This helps us with packing and polarity marking.