... the hole High Pressure RC Drilling bit Bit for down-the-hole drilling, air reverse circulation drilling in mining exploration, ... civil engineering, water well drilling, geothermal well drilling, reverse circulation drilling.Bit ... etcConvex Front, Flat Front, Concave Front, Concave DGR Front etc.Bit Dia. 85mm, 90mm, 95mm, 102mm, 105mm, 115mm, ...