... 5.Maintenance convenience A, ZQS-50/1.6Portable Pneumatic Drilling Machine is introduced, Basic performance unit Basic performance parameters model ... .Great torque5.Maintenance convenienceZQS-50/1.6 portable pneumatic drilling machine has nine main features:more powerful,light weight,Safety ... It is mainly used for side bolt supporting and drilling blasting hole in coal tunnel and coal-rock tunnel.D, ...