Testing of lubricants ; testing by the shell four - ball tester ; determination of welding load of consistent lubricants 潤滑劑檢驗.用殼牌公司的四球試驗儀檢驗.潤滑脂焊接
Testing of lubricants ; testing by the shell four - ball tester ; determination of wear characteristics for consistent lubricants 潤滑劑檢驗.用殼牌公司的四球試驗儀檢驗.潤滑脂磨損