← Glossary

1.8550

X45CrSi9-3

1.8550 (X45CrSi9-3) is a heat-resistant [[glossary:kaltarbeitsstahl|tool steel]] with 0.45 % [[element:C|carbon]], 9 % [[element:Cr|chromium]], and [[element:Si|silicon]] — a valve steel also used as a tool steel. The silicon improves [[glossary:zunderbestaendigkeit|scale]] resistance at high temperatures. Uses: valves, heat-resistant components, tools for high temperatures.

AI Transparency (EU AI Act): Created on the basis of our own many years of practical experience in welding technology, with the help of AI, and reviewed editorially.

© 2026 Welder-World. All content is for training and continuing education and does not replace a certified welding procedure specification.