← Glossary

1.1654

C125W

1.1654 (C125W) is an unalloyed [[glossary:kaltarbeitsstahl|tool steel]] with 1.25 % [[element:C|carbon]] — the highest carbon content among unalloyed tool steels. It reaches maximum [[glossary:haerte|hardness]] but is extremely brittle. Use: files, razor blades, watch spring stamping tools, where you need max edge hardness and low stress.

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.