With greatest external diameter not exceeding 609,6 mm
Butt welding elbows and bends, of iron or steel, with greatest external diameter < 609,6 mm (excl. cast iron or stainless steel products)
Butt welding fittings of iron or steel, with greatest external diameter < 609,6 mm (excl. cast iron or stainless steel products, elbows, bends and flanges)