This standard fixes for keying by thin inclined keys the dimensional characteris ics of the grooves and flats in the hub and the shaft as well as the relationship to be respected between the diameter of the shaft and the section of the key. The dimensions of thin inclined keys are given in NBN E 27-710. Keying with inclined keys requires adjustment of the key. The dimensions and tolerances given in this standard have been set in such a way that this adjustment is possible in all cases.