juptonstone
Member at Large...
According to Sure that is the pressure exerted by the stylus on the record groove... article linked here
http://shure.custhelp.com/app/answers/detail/a_id/4135/~/stylus-wear-and-record-wear
http://shure.custhelp.com/app/answers/detail/a_id/4135/~/stylus-wear-and-record-wear