20mm x 10mm x 2mm 

N52 Thin Rare Earth Neodymium Magnet Blocks


Specification:
Dimensions: 20mm x 10mm x 2mm thick
Tolerances: ±0.1mm x ±0.1mm

Plating/Coating: Ni-Cu-Ni (Nickel)
Magnetization Direction: Axial (Poles on Flat Ends)
Max Operating Temp: 176ºF (80ºC)
Pull Force: approx. 5.8 LB
 
Material Features:
Magnets are made of a brittle material. These magnets are not as strong as steel.  They are more like a brittle ceramic.  If you let two magnets slam together, they can crack and break.