7304.29.31.20 - Having a wall thickness of 12.7 mm or more

This HTS category, 7304.29.31.20, specifically covers seamless tubes and pipes, also known as casing, of iron or steel, designed for use in drilling for oil or gas. The defining characteristic of this classification is a wall thickness measuring 12.7 millimeters or greater. These items are typically constructed from alloy steel and are threaded or coupled for connection in wellbore operations.

This category is distinguished from its sibling, 7304.29.31.10, by the crucial physical attribute of wall thickness. While both classify casing used in oil and gas drilling with an outside diameter less than 215.9 mm, this node designates products with a substantial wall thickness of 12.7 mm or more, indicating a requirement for greater structural integrity and pressure resistance.

As this is a leaf node within the HTS structure, there are no further subcategories. Therefore, the classification is definitively determined by the combined criteria of material (alloy steel), application (oil and gas drilling casing), construction (seamless, threaded/coupled), outside diameter (less than 215.9 mm), and the specified wall thickness (12.7 mm or more). Items meeting all these precise specifications are to be classified under this code.