For extreme conditions hard rock conditions such as Limestone, Marble, Granite and Medium to Hard Shale (10,000 PSI to 28,000 PSI Rock) TCI IADC 500 series sealed bearing cutters. Wear pads up to 16ƒÆ’†€™ƒ€š‚¢¡ƒ¢¡‚ sizes and a Ring...