scope:

This part of ISO 3506 specifies the mechanical properties of tapping screws made of austenitic, martensitic and ferritic steel grades of corrosion-resistant stainless steels when tested over an ambient temperature range of 10 °C to 35 °C. Properties will vary at higher or lower temperatures.
It applies to tapping screws with threads from ST2,2 up to and including ST8 in accordance with ISO 1478.
It does not apply to screws with special properties such as weldability.
NOTE The designation system of this part of ISO 3506 may be used for sizes outside the limits laid down in this clause (e.g. d > ST8), provided that all applicable mechanical and physical requirements of the property classes are met.
This part of ISO 3506 does not define corrosion or oxidation resistance in particular environments. However, some information on materials for particular environments is given in Annex C. Regarding definitions of corrosion and corrosion resistance see ISO 8044.
The aim of this part of ISO 3506 is a classification into property classes of corrosion-resistant stainless steel fasteners.
Corrosion and oxidation performances and mechanical properties for use at elevated or sub-zero temperatures should be agreed between user and manufacturer in each particular case. Annex D shows how the risk of intergranular corrosion at elevated temperatures depends on the carbon content.
All austenitic stainless steel fasteners are normally non-magnetic in the annealed condition; after cold working, some magnetic properties may be evident (see Annex E).