20x4mm sintered round N50 grade neodymium ring magnet with 5mm countersunk hole *new*

A neodymium magnet (also known as NdFeB, NIB or Neo magnet), the most widely used type of rare-earth magnet, is a permanent magnet made from an alloy of neodymium, iron and boron to form the Nd2Fe14B tetragonal crystalline structure. Neodymium magnets are developed independently in 1982 by General Motors and Sumitomo Special Metals. Neodymium magnets are the strongest type of permanent magnet which is commercially available. They have replaced other types of magnets in the many modern applications and products that require strong permanent magnets, such as motors in cordless tools, hard disk drives and magnetic fasteners.

NIB magnet technical specifications:

• Dimensions:
  • 20x4mm
• Shape:
  • Circular ring
• Hole diameter:
  • 5mm countersunk hole
• Material:
  • Sintered Nd2Fe14B (neodymium, iron, and boron)
• Grade:
  • N50 (one of the strongest available grade)
• Remanence (B_r) (measures the strength of the magnetic field):
  • 1,4T
  • 14000G
• Coercivity (H_ci) (the material's resistance to becoming demagnetized):
  • 876kA/m
  • 11000T
• Energy product (BH_max) (the density of magnetic energy):
  • 382kJ/m³
  • 48kA/m
• Curie temperature (TC) (the temperature at which the material loses its magnetism):
  • 310...400°C (590...752°F)
• Max operating temperature:
  • 80°C (176°F)
• Surface finish:
  • Ni-Cu-Ni (nickel-copper-nickel)

These magnets are brittle! This means do not let them slam against each others or any other metal objects they attract. Also when you fasten them with screw, use your power of thinking and hand tighten the screws! Or else... You get more, but smaller magnets. Feels pointless to say, but we say it anyways... Do not eat these!