Material number

 Defined number for the unique designation of materials.

According to this definition, the material numbers start as follows:

1. Steel and iron with the main groups 0 (pig iron and cast iron) and 1 (steel)
2. Non-ferrous metals (heavy metals)
3. Non-ferrous metals (light metals, e.g. aluminum and aluminum alloys)
4. Sinter metals

The number for steel is defined in DIN EN 10027-2. Material numbers are structured as follows:

1. WW. XX(XX). YZ with

1 = material number for steel
WW = steel group number (e.g. 05 = unalloyed high-grade steel with C = 0.25 to 0.55%)
XX(XX) = sequence number
Y = steel production process (e.g. 9 = electric steel)
Z = treatment condition (e.g. 1 normalized)

Additional references:
Material condition