Hollow Bars AISI 304L 316L Applications for Hollow Bars: Actuators and Valves That is Flow Meters / Valves / Filters / Vessels / Sample Probes. Pumps and Compressors Then Suction Devices / Hydraulic Cylinders / Pump Bodies / Compression Bodies. Axles and Shafts Namely Rollers / Guides / Compasses / Shafts / Collars / Hubs …