... 20 years history Milled Tooth Rock Roller Bits: 7 7/8 to 14 1/2 ModelTCI BIT, STEEL TOOTH BITIADC CODE 116 ... 537 547 516 536 535available sizes:From 2 7/8 to 26”larger sizes for hole opener bit ,reamer bitadvantagemost favourable price ... and drilling equipment for petroleum&gas ,water well ,mining and tectonic industries ,oil field, construction, geothermal, directional boring, and underground ...