The outer sole material is the deciding factor. If the bottom surface that contacts the ground is leather or composition leather, the article falls under 640351 or 640359 (split by ankle coverage). If the outer sole is rubber or plastics with a leather upper, it falls under 640391 or 640399. The upper material alone does not determine the subheading.

A protective metal toe-cap directs classification to 640340 regardless of ankle height or sole material, provided the upper is leather. The safety-footwear subheading takes precedence over the general ankle-coverage subheadings when the toe-cap requirement is met.