7304.29.31.30 - Having a wall thickness less than 12.7 mm

This HTS category, 7304.29.31.30, specifically classifies seamless pipes and tubes of iron or steel designed for drilling for oil or gas. These are further defined as casing, belonging to the "other alloy steel" subcategory, and are characterized by being threaded or coupled for connection. Crucially, this classification is for casing with an outside diameter ranging from 215.9 mm to 285.8 mm and a wall thickness that is less than 12.7 mm.

The primary distinguishing factor for this classification lies in its specific wall thickness. It differentiates from its sibling category, 7304.29.31.40, which covers casing of the same outside diameter and material type but possesses a wall thickness of 12.7 mm or greater. Both classifications fall under the broader heading of casing used in oil and gas drilling, are made from alloy steel, and are threaded or coupled, but the precise wall thickness is the determinant for entry into either 7304.29.31.30 or its sibling.

As a leaf node, this classification does not have further subcategories. Therefore, classification decisions within this specific code rely entirely on meeting the stated criteria for outside diameter, wall thickness, material type (other alloy steel), and functional characteristic (threaded or coupled for oil and gas drilling casing). Importers and exporters must meticulously verify these physical and functional attributes to ensure correct classification.