20mm x 3mm x Hole 3mm Neodymium Countersunk Magnet – N52 Grade 

Key Features:

• Dimensions: 20mm Outer Diameter × 3mm Thickness × 3mm Inner Hole Diameter
• Countersink Profile: Accommodates standard #2 or M3 flathead wood/machine screws for flush mounting
• Precision Tolerance: ±0.05mm 
• Magnet Grade: N52 
• Pull Force: Approx. 11.7 lbs 
• Coating: Nickel-Copper-Nickel (Ni-Cu-Ni) triple-layer plating
• Magnetization: Axially magnetized (Poles on the flat circular faces, countersunk on the North or South face)

Material Description:

Our 20mm x 3mm countersunk N52 ring magnets provide an expansive surface footprint for demanding installation environments where traditional adhesives fail. The 20mm broad outer diameter significantly increases lateral stability, preventing the magnet from pivoting, sliding, or pulling out under heavy shear loads. Designed with an integrated 3mm countersunk hole, it allows a flathead screw to sit completely flush with the magnet's surface, facilitating seamless metal-to-magnet contact and maximizing the available 13.5 lbs of holding force.

Handling Advice: DANGER: Wide, thin countersunk magnets require precise handling. Sintered neodymium is inherently brittle like ceramic. Over-tightening mounting screws with power tools will crack or split the magnet across the center hole—always hand-tighten with care. These magnets also possess high snap velocity; never let them free-fly together or strike steel surfaces violently, as they will shatter into sharp fragments.

Warnings and Safety Information:

• Pinch Hazard: Strong enough to cause painful skin pinches or blood blisters. Handle with professional care.
• Fragility Hazard: Do not over-tighten screws. High impact from snapping together WILL fracture the ring profile.
• 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:

• Low-profile hidden latches for commercial cabinetry, display cases, and heavy secret doors
• Mechanical anchoring for large removable wall panels, acoustic partitions, and ceiling signage
• Flush-mounted signage systems and quick-swap retail exhibition presentation frames
• High-vibration workshop tool organization, custom jigs, and removable machine guards
• Heavy-duty 3D-printed enclosure mounts requiring wide-area structural attachment