DIN 557 - 1994 Square Nuts-Product Grade C
Equivalent norm: UNI 5597
| Legend | Making |
| P=pitch | Carbon Steel:5 |
| K=height of the nut | Thread: |
| D=the nominal diameter of the thread | Surface:BLK,ZP,HDG,etc |
| E=The length of the diagonal | |
| S=The length of the flat |

DIN 562 - 2013 Square Thin Nuts, Product Grade B
