Use these fittings only with our standard tubing and hose. Our standard tubing is 5/16" O.D. seamless heavy-wall tubing, C1010 steel, cold drawn, fully annealed, .065" wall thickness, 22,800 psi minimum burst pressure. SAE O-ring fittings are limited to 5000 psi operating pressure and limit the entire system to that pressure. Other brands of power-workholding components are usually not totally leak-free, so they should not be used on pallet fixtures disconnected from the hydraulic power source.