High-quality high- elastic rigid automatically adjustable 1,Connectors Material: low carbon alloy steelCraft: high pressure molding, thermal ... connector, hand-held pneumatic drilling machine connector, reducer union, core barrel reducer union, and so on.2,Connectors No.Product NameSpecifications ... union63--73Connect drill rods10Reducer union73-89Connect drill rods3,Connectors RUILONG Coal mining ...