McMaster 5862K939 Nickel-Plated Neodymium Magnet, N45, 1/4" Thick × 1/2" Wide × 2" Long, 28 lb Pull, 2 Countersunk Holes

Unmatched strength in a compact shape. These magnets have the highest strength-to-size ratio of any magnet, delivering powerful pull force even in tight spaces. Their flat, rectangular shape creates a strong, even pull across surfaces and fits easily into slots or grooves. However, they may lose magnetic strength at high temperatures. Also known as rare earth magnets.

Warning — Maximum pull ratings are based on direct contact with rust-free, unpainted iron surfaces. Variations in material condition will significantly reduce these ratings. Do not use for lifting over people.

Magnetized Through Thickness — Magnetized from one flat face to the other, these magnets deliver a concentrated magnetic force. They’re best for direct contact with flat surfaces.

Nickel Plated — With a nickel-plated finish, these magnets stand up to solvents, salt water, and chemicals better than uncoated neodymium. The plating may wear off over time, so these are not recommended for applications with a lot of friction or wear.