40x20x10 mm Neodymium Block Magnet
A 40x20x10 mm neodymium block magnet is 40 mm long, 20 mm wide and 10 mm thick. It is a standard size in the Rami Technics stock list (code BLOK1053) and is supplied in grades from N35 to N52, with HRE-free and Dy/Tb options, in nickel, epoxy or gold coating.
Specification
| Shape | Block magnet (sintered NdFeB) |
|---|---|
| Nominal size | 40x20x10 mm |
| Magnetisation | Normally through the 10 mm thickness; other directions on request |
| Volume | 8,000 mm³ (8.000 cm³) |
| Weight each | about 60.0 g (nominal size, density 7.5 g/cm³, before coating) |
| Pieces per kilogram | about 17 |
| Grades | N35-52 / HRE FREE / Dy&Tb |
| Coating | Nickel, Epoxy, Gold |
| Stock code | BLOK1053 |
Where this size is used
A magnet of this size is used for holding plates, fixtures, separators and heavier assemblies. It is strong enough to cause injury and can shatter if it snaps onto steel or another magnet: keep pieces apart and wear gloves.
The shape sits between thin and tall. Its temperature margin is moderate, so state your highest working temperature when you ask for a quote.
Choosing the grade and coating
Start from the working temperature and the environment, not from the highest N number. Standard grades are for ordinary indoor temperatures; the letters after the number (M, H, SH, UH) raise the temperature limit. Nickel is the usual coating for dry indoor use; epoxy is the usual choice for humidity, and gold is used for appearance and some medical or electronic parts. See the Selection Guide and the Coatings guide for details.
Questions about the 40x20x10 mm block magnet
How much does a 40x20x10 mm neodymium block magnet weigh?
About 60.0 g each, or roughly 17 pieces per kilogram. This is calculated from the nominal size and a density of 7.5 g/cm³, the same value as the Rami Technics weight calculator, before coating.
Which grade should I choose for a 40x20x10 mm block magnet?
Grades N35 to N52 are available, with HRE-free and Dy/Tb options. Choose by working temperature first, then by the force you need. If the part gets warm, ask for a suffix grade (M, H, SH or UH). Tell us the temperature and the application and we will suggest one.
Can I order this size with a different grade, coating or tolerance?
Yes. Rami Technics supplies custom sizes and OEM programmes as well as stock sizes. Send the drawing or the dimensions, the grade, the coating, the magnetisation direction and the quantity, and we reply with a quote.
Other block magnet sizes
Important notice: sizes are nominal, and weights are calculated from them with a density of 7.5 g/cm³ before coating, so real pieces differ slightly. This page is general technical information, not a specification, an offer or a guarantee of performance. Confirm the grade, tolerance and force against the datasheet and test a sample in your application.