The present Standard corresponds in substance to the ISO Draft
ISO/DIS 3117-1973
Tangential keying
While it is true that this ISO Draft deals only with tangential keys and keyways for constant loads (DIN 271), it none the less indicates that, for alternating shock loads, tangential keys with t = 0.1 d and b = 0.3 d are recommended. As compared with the April 1924 Issue of DIN 268, the following amendments and additions should be noted:
a) The shaft diameter were partly changed to conform to ISO Recommendation R 775 and also to correspond to DIN 748 Part 1.
b) While existing cross-sections of keys and keyways have been retained, changes have in some cases been made in the slope of the keys and in the rounding of the bottom of the keyways.
c) Shaft diameters above 630mm have been omitted. Should it be necessary, however, tangential keys and keyways for larger shaft diameters can be determined from the formulae quoted.
d) The contents of the Standard have been revised and supplemented, e.g., by the inclusion of an example of designation and details of materials.