When a weapon arm needs to swap cleanly on a Space Marine, or a scrapbook cover has to close flat without a visible lump, the magnet doing the job has to be exactly right — not approximately right. These 4×1mm N52 discs are sized for applications where a millimeter of tolerance separates a clean build from a redo.
Each magnet is 4mm in diameter and 1mm thick — about the size of a sesame seed in footprint, as thin as a credit card edge. The Ni-Cu-Ni triple-layer plating gives a smooth silver finish that won't scratch surrounding surfaces or corrode in humid workshop conditions. Magnetization runs axially through the 1mm thickness, so both flat faces are active poles. Dimensional tolerance is ±0.1mm — meaningful when you're drilling to fit.
For wargaming and miniature modeling: 4mm is the standard drill diameter for 28mm scale figures — shoulder joints, weapon swaps, arm attachments. N52 grade means each magnet grips a steel surface with up to 0.45 lbs pull force; two magnets facing each other effectively double that. They sit flush in a 4mm drill channel with a drop of CA glue, hold polarity reliably, and survive transport in foam cases without loosening.
For scrapbooking and paper crafts: at 1mm thick, a pair of these discs disappears under a single sheet of cardstock. Press them into a handmade mini album spine or behind a card flap and the closure snaps shut with no visible hardware. For 3D printing: design your pocket at 4.1–4.2mm diameter for a snug press-fit — the ±0.1mm tolerance makes consistent slot sizing practical across a full print run.
Not suitable for children under 14. Keep away from pacemakers and implanted electronic devices. Small magnets can be a pinching hazard — handle with care. If swallowed, magnets can attract across intestinal walls and cause serious internal injury; seek immediate medical attention.