2.4mm 5356 aluminium TIG rod sold by the kg or part thereof. 5356 aluminium TIG rod has become the most commonly used of all aluminum filler alloys because of its good strength. It is designed to weld 5xxx series structural alloys and 6xxx series extrusions, basically anything other than castings, because castings are high in silicon. Its one limitation is that 5356 is not suitable for service temperatures exceeding 65 degrees Celsius. The formation of Al2Mg at elevated temperatures at the grain boundaries makes the alloys prone to stress corrosion. For components that will be anodized after welding, 5356 is recommended over 4043, which turns jet black when anodized.