This part of ISO 3506 specifies the mechanical properties of nuts made of austenitic, martensitic and ferritic grades of corrosion-resistant stainless steels when tested over an ambient temperature range of 15 °C to 25 °C. Properties will vary at higher or lower temperatures.

It applies to nuts

• with nominal thread diameters (d) up to and including 39 mm;
• of triangular ISO metric threads with diameters (d) and pitches in accordance with ISO 68-1, ISO 261 and ISO 262;
• of any shape;
• with width across flats as specified in ISO 272;
• with nominal heights greater than or equal to 0,5 d.

It does not apply to nuts requiring properties such as

• locking abilities;
• weldability.

This part of ISO 3506 does not define corrosion or oxidation resistance in particular environments.

The aim of this part of ISO 3506 is a classification into property classes of corrosion resistant stainless steel fasteners. Some materials can be used at temperatures down to −200 °C, some can be used at temperatures up to +800 °C in air. Information on the influence of temperature on mechanical properties is found in annex D.

Corrosion and oxidation performances and mechanical properties for use at elevated or sub-zero temperatures must be the subject of agreement between user and manufacturer in each particular case. Annex E 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 F).