... convenience 5.High drilling efficiency A, ZQSJ-90/2.4 Portable Pneumatic Flame-proof Drilling Machine is introduced, Performance parametersunitnumericalRated pressureMPa0.5Rated ... in coal lane and coal-rock lane. With reverse rotated action, it can take out the drill rod and bit easily.It ... technology,wins the world by excellent quality.Quality of drill rod and drill is first-class,the ture gold is not ...