The H65 brass national standard has the following five hardness states, which are: soft, 1/4 hard, 1/2 hard, hard and extra hard. The specific hardness standards and corresponding international grades are as follows:

1. Soft state: H65M -- hardness below 100HV (soft state) -- corresponding to international brand C2680-O
2. 1/4 hard: H65-Y4 -- hardness 75-125HV -- corresponding to the international grade C2680-1/4H
3. 1/2 hard: H65-Y2 -- hardness 85-145HV -- corresponding to the international brand C2680-1/2H
4. Hard state: H65-Y -- hardness 105-175HV -- corresponding to the international brand C2680-H
5. Extremely hard: H65-T -- hardness ≥145 -- corresponding to the international brand C2680-EH