TCI 8,5" tricon tricone rock roller bit by ISO9001&API best ... 537 547 516 536 535available sizes:From 2 7/8 to 26”larger sizes for hole opener bit ,reamer bitadvantagemost favourable price ... , Sands, Salts etc.1187.3~346.17 3/8~13 5/8441~735120~50softClays, Soft Shale, Marl, Sands, Salts etc. ... 7/8245-490100-50187.3~346.17 3/8-13 5/8490-78490-40Medium softShale, Marl, Sandstone, Soft Limestone etc. ...