... -hole drilling air reverse circulation drilling. High Pressure RC Drilling bit Bit for down-the-hole drilling, air reverse circulation drilling in ... engineering, water well drilling, geothermal well drilling, reverse circulation drilling.Bit Front designs:Complete compatible to be used with DHD hammerDHD330 ... .Convex Front, Flat Front, Concave Front, Concave DGR Front etc.Bit Dia. RC Drill Hammer and ...