10pcs 15mm x 4mm x Hole 4mm Neodymium Straight Ring Magnet – N52 Grade 

Key Features:

• Dimensions: 15mm Outer Diameter × 4mm Thickness × 4mm Inner Hole Diameter
• Straight Hole Profile: Uniform 4mm cylindrical inner diameter (no countersink) for shaft-mounting, pinning, and bolt-through setups
• Precision Tolerance: ±0.05mm 
• Magnet Grade: N52 
• Pull Force: Approx. 11.6 lbs 
• Coating: Nickel-Copper-Nickel (Ni-Cu-Ni) triple-layer plating for superior durability
• Magnetization: Axially magnetized (Poles on the flat circular faces, providing uniform flux distribution)

Material Description:

Our 15mm x 4mm uniform N52 ring magnets are engineered specifically for complex mechanical, automation, and industrial fabrication projects where a non-countersunk through-hole is mandatory. The broad 15mm outer diameter significantly increases lateral stability, preventing the magnet from shifting or twisting under heavy shear loads. The straight 4mm inner bore allows this magnet to be seamlessly pressed onto steel axles, utilized in magnetic bearings, or held securely via non-magnetic machine bolts and pins. Because both circular faces remain entirely flat, this ring can be stacked back-to-back to compound magnetic force or used in alternating arrays for high-torque magnetic couplings and contactless sensory drive systems.

Handling Advice: DANGER: Industrial-strength ring profiles require careful, controlled installation. Neodymium is inherently brittle like ceramic. While straight cylindrical holes distribute mechanical clamping force much more evenly than countersunk pockets, over-tightening bolts or pins can still crack the core—always hand-tighten with care. These magnets also possess immense snap velocity; never let them free-fly together or snap onto steel tools, as they will shatter violently upon impact.

Warnings and Safety Information:

• Crush Hazard: High risk of serious skin and finger pinches or blood blisters. Handle with industrial focus.
• Brittle Core Warning: Sintered neodymium is fragile. High-impact collisions or dropping onto hard surfaces will fracture the ring wall.
• CHOKING HAZARD: Keep securely stored and out of reach of children and pets.
• Medical Safety: KEEP AWAY from pacemakers and sensitive medical implants at all times.

Applications:

• High-torque magnetic couplings, rotary encoders, and contactless drive linkages for automated manufacturing
• Industrial magnetic bearings, guide rollers, and shaft-mounted rotational assemblies
• Pass-through sensor rings for heavy automation, pneumatic pistons, and Hall-effect electronics
• Secure bolt-through anchoring for custom machinery enclosures, heavy equipment hatches, and guarding panels
• High-vibration shop-tool organization, magnetic separator assemblies, and custom mounting jigs