The OK Tigrod 13.38 is a non-copper coated, low alloyed, 9CrMoVN rod for the GTAW of high-temperature steels and steels for hot hydrogen service, especially in oil refineries. It is particularly effective when used with 9% Cr steels, such as P 91/T 91 steels. The alloy is modified in terms of the limits for impurity elements and is extremely "clean". This meticulous modification results in improved strength levels that are noticeable both at room temperature and at higher temperatures. AWS has recognised this improvement and changed the classification for this product from A5.9 ER505.