Most recent
DIN 979:2013
Hexagon thin slotted and castle nuts - Metric coarse and fine pitch thread, product grades A and B
The document contains dimensional and technical requirements of hexagon thin slotted and castle nuts; metric coarse and fire thread, with nominal thread sizes from 6 mm to 52 mm, in product grades A and B and specifies their designation.
Deutsches Institut für Normung [din]