... ' rings. The holes are centrally located. The countersunk ring allows for the magnet to be screwed onto another item ... N28AH-N35AH220°C (428°F)Magnet ShapeDisc, Cylinder, Block, Ring, Countersunk, Segment, Trapezoid, Irregular shapes and more. Customized shapes ... Strong Magnets are available.Magnet CoatingNi-Cu-Ni, Nickel, Zn, Gold, Silver, Copper, Epoxy, Phosphating, Chemical, PTFE, Parylene Everlube, ...