according to ISO 898, part 5: 2012 table 2
b) In case of dispute, the product analysis applies.
c) Free-cutting steel may be used, with maximum lead content 0,35 %, maximum phosphorus content 0,11 % and maximum sulfur content 0,34 %.
d) Steel with a maximum lead content of 0,35 % may be used.
e) For d ≤ M16 only.
f) This alloy steel shall contain at least one of the following elements in the minimum quantity given: chromium 0,30 %, nickel 0,30 %, molybdenum 0,20 %,
vanadium 0,10 %. Where elements are specified in combinations of two, three or four and have lower alloy contents than those given above in this footnote,
the limit value to be applied for steel class determination is 70 % of the sum of the individual limit values shown above in this footnote for the two, three or
four elements concerned.