ISO 3506-2:2020 pdf free download.Fasteners一Mechanical properties of corrosion-resistant stainless steel fasteners Part 2: Nuts with specified grades and property classes.
— D for duplex (austeniticferritic), and
— a digit which specifies the range of chemical compositions within this stainless steel group.
The chemical compositions of stainless steel groups and grades classified in Figure 1 are specified in Table 2.
5.2.3 Designation of property classes (second block) for regular nuts (style 1) and high nuts (style 2)
The designation of the property class (second block) consists of a number corresponding to 1/10 of the stress under proof load of the nut in accordance with Table 3 or4. it also corresponds to the appropriate stainless steel property class of the bolt, screw and stud with which it should be mated.
EXAMPLE I A2-70 specifies an austenitic stainless steel nut, work hardened, with stress under proof load of 700 MPa, for nuts with lull loadability (m  0,8D).
EXAMPLE 2 Cl-hO specifies a martensitic stainless steel nut, quenched and tempered, with stress under proof load of 1100 M Pa, for nuts with full loadability (m  0,8D).
5.2.4 Designation of property classes (second block) for thin nuts (style 0)
The designation of the property class (second block) for thin nuts (style 0) consists of a digit and a number, specified in the following ways:
— the first digit is zero, indicating that the loadability of the thin nuts is reduced in comparison with the loadability of a regular or high nut in accordance with 52.3. and therefore thread stripping can occur when overloaded,
— the following number corresponds to 1/10 of the stress under proof load of the nut on a hardened test mandrel in megapascals; it also corresponds to half of the appropriate property class of the stainless steel fastener with which the thin nut should be mated.
EXAMPLE A4.040 specifies an austenitic stainless steel thin nut, with the same material and manufacturing process (work hardened, high strength) as a regular nut A4-80, but with stress under proof load of 400 MPa (reduced loadability) because of its height (m < 0,80 D). 6 Design of bolt and nut assemblies Property class combinations of nuts to bolts, screws and studs shall be in accordance with Table 1.ISO 3506-2 pdf download.