CNC Process Precise Hydraulic Cylinder Parts 1)ISO9001:2008 certificated 2)material:copper,aluminum,stainless steel,iron. Changzhou Bowei Precision ... a factory,specialized in hydraulic,valve and automobile parts.The parts we manufacturing and processing belong to nonstandard ... CentresIf you want to customize some parts,especially valve parts,hydraulic parts,automobile parts,etc,welcome to Bowei.