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 ℃ to 25 ℃. 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 ℃, some can be used at temperatures up to +800 ℃ 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).
ISO 3506-2:1997 history
2020ISO 3506-2:2020 Fasteners — Mechanical properties of corrosion-resistant stainless steel fasteners — Part 2: Nuts with specified grades and property classes
2009ISO 3506-2:2009 Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts
1997ISO 3506-2:1997 Mechanical properties of corrosion-resistant stainless-steel fasteners - Part 2: Nuts