Retaining magnet rod-shaped 52.5-nd-16-m8, w/stud & rubber jacket, magnetic surface, .63″ dia. Steel gn 52.5 magnets are a shielded magnetic assembly with rubber jacket. They are especially suitable for applications where the surface is easily marred. Also, these magnets have an increased coefficient of friction, which creates high lateral retaining force. Temperature resistant to 175 f (80c).