7304.24.40.40 - Having a wall thickness of 12.7 mm or more

This HTS category, 7304.24.40.40, specifically classifies seamless casing pipes made of iron or steel, intended for use in drilling for oil or gas, when these pipes are constructed from stainless steel and possess a wall thickness of 12.7 millimeters or greater. The classification is further narrowed by the requirement that the casing must have an outside diameter ranging from 215.9 mm to 285.8 mm, inclusive.

This designation is distinct from its sibling category, 7304.24.40.30, which covers similar stainless steel casing pipes for oil and gas drilling but is characterized by a wall thickness *less than* 12.7 mm. Therefore, the critical distinguishing factor at this level is the minimum wall thickness.

As a leaf node in the HTS structure, this category represents a specific end-point for classification. It signifies that no further subdivisions exist for casing pipes meeting all the preceding criteria: seamless construction, stainless steel material, oil/gas drilling application, specific outside diameter range, and a wall thickness of 12.7 mm or more. Importers and exporters should confirm these precise physical attributes to ensure accurate classification.