EN Alloys Numbering System
The system uses 6 characters.
The first character is a C for Copper-based alloys.
The second character is a letter from the table below.
The third, fourth and fifth characters comprise a 3-digit number, which with a sixth character (a letter) indicate the alloy group. These number series and corresponding letters are also shown in the table below.
An example is CW614N.
| Character/Digits | Key | | B | Ingot for re-melting to produce cast products |
| C | Cast Products |
| F | Filler Materials for Brazing and Welding |
| M | Master Alloys |
| R | Refined Unwrought Copper |
| S | Scrap |
| W | Wrought Products |
| X | Non-Standardised Materials |
| 000 to 099 A or B | Pure Copper |
| 100 to 199 C or D | Copper Alloys with less than 5% added elements |
| 200 to 299 E or F | Miscellaneous Copper Alloys with more than 5% added elements |
| 300 to 349 G | Copper-Aluminium Alloys |
| 350-399 H | Copper-Nickel Alloys (Cupro-Nickel) |
| 400 to 449 J | Copper-Nickel-Zinc Alloys |
| 450 to 499 K | Copper-Tin Alloys |
| 500 to 599 L or M | Copper-Zinc Alloys - Binary |
| 600 to 699 N or P | Copper-Zind-Lead Alloys |
| 700 to 799 R or S | Copper-Zinc Alloys - Complex |