CPV code 44164000 designates Casing and tubing in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
44164000 sits under 44160000 (Pipeline, piping, pipes, casing, tubing and related items) and groups 3 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.