3-Pack Round Neodymium Magnet with Countersunk Hole, 80 LBS Pulling Force, 1.65" Diameter Extremely strong Neodymium Magnet with up to 80 lbs pulling force on contact with 1/4" thick steel. Magnet is neodymium iron boron (NbFeB) rare earth with Nickel-Copper-Nickel coated steel cup. Countersunk hole for easy use with screws, eyebolts, hooks, and other types of fasteners. Coated steel cup provides protection for the magnet and helps to prevent chipping or cracking. Package of 3 magnets with diameter of 1.65 and thickness of .35