BS EN ISO 3506-2:2020 Fasteners. Mechanical properties of corrosion-resistant stainless steel fasteners. Nuts with specified grades and property classes

BS EN ISO 3506-2:2020

Fasteners. Mechanical properties of corrosion-resistant stainless steel fasteners. Nuts with specified grades and property classes

Status : Current   Published : April 2020



What is BS EN ISO 3506-2:2020 about?

This is the second in a six-part series of international standards on the mechanical and physical properties of stainless steel fasteners. BS EN ISO 3506-2:2020 covers specific types of nut.

Who is BS EN ISO 3506-2:2020 for?

  • Manufacturers and distributors of stainless steel fasteners
  • Structural and consulting engineers
  • Construction and civil engineering contractors and larger sub-contractors
  • Test houses and laboratories
  • Industries associated with oil and gas production and distribution

Why should you use BS EN ISO 3506-2:2020?

It specifies the mechanical and physical properties of nuts with coarse pitch thread and fine pitch thread, made of corrosion-resistant stainless steels and when tested at the ambient temperature range of 10 °C to 35 °C.

It specifies property classes in relation to austenitic, martensitic, ferritic and duplex (austenitic-ferritic) steel grades for nuts and applies to nuts of any shape with:

—      ISO metric thread in accordance with  ISO 68-1

—      Diameter/pitch combinations in accordance with  ISO 261 and ISO 262

—      Coarse pitch thread M5 to M39, and fine pitch thread M8×1 to M39×3,

—      Thread tolerances in accordance with ISO 965-1 and ISO 965-2

—      Specified property classes, including proof load

—      Different nut styles: thin nuts, regular nuts and high nuts

—      A minimum nut height m ≥ 0,45D

—      A minimum outside diameter or width across flats s ≥ 1,45D and able to mate with bolts, screws and studs with property classes in accordance with ISO 3506-1

  Together with BS EN ISO 3506-1:2020 and BS ISO 3506-6:2020 it

provides additional advice and guidance for most applications where these products will be required. 

There are other standards which deal specifically with specialized areas such as oil and gas but this considerably revised document provides an excellent foundation for any assessment.

NOTE: This standard does not specify requirements for functional properties such as torque/clamp force properties, prevailing torque properties, or weldability.

BS EN ISO 3506-2:2020 can help users achieve UN Sustainable Development Goal 9 on industry, innovation and infrastructure because it contributes to the building of resilient infrastructure.


What’s new about BS EN ISO 3506-2:2020?

The standard has been revised to  add duplex (austenitic-ferritic) stainless steels for property classes 70, 80 and 100 . The main changes in BS EN ISO 3506-2:2020 are:

a) Annexes common to several parts of the ISO 3506 series have been withdrawn from this document and are now included in a new document (ISO 3506-6)

a)       Duplex (austenitic-ferritic) stainless steels for property classes 70, 80 and 100 have been added

b)      Property class 100 for austenitic stainless steel grades as well as grade A8 have been added

c)       Information for nut styles has been added

d)      Design of stainless steel bolt and nut assemblies, and design principles of stainless steel nuts have been added

e)      Finish has been improved

f)        Calculated proof load values and rounding rules have been added

g)       Requirements and guidance for inspection procedures have been added

h)      Thread dimensions of the test mandrel for proof load have been added

i)        Operational temperature ranges have been clarified

j)        Test methods for proof load and hardness have been improved

k)       Nut marking and labelling especially for thin nuts with reduced loadability have been added

Structure and content of this document have been brought in line with ISO 898-2

Standard NumberBS EN ISO 3506-2:2020
TitleFasteners. Mechanical properties of corrosion-resistant stainless steel fasteners. Nuts with specified grades and property classes
Publication Date27 April 2020
Normative References(Required to achieve compliance to this standard)ISO 6508-1, ISO 1891-4, ISO 6506-1, ISO 898-1, ISO 6892-1, ISO 6507-1, ISO 16228, ISO 3506-6, ISO 7500-1
Informative References(Provided for Information)ISO 965-1, ISO 16048, ISO 261, ISO 286-2, ISO 3506-1, ISO 3506-5, ISO 898-2, ISO 262, ISO 965-2, ISO 4033, ISO 16426, ISO 68-1, ISO 4032, EN 10088 (all parts)
ReplacesBS EN ISO 3506-2:2009
International RelationshipsEN ISO 3506-2:2020,ISO 3506-2:2020
Draft Superseded By18/30333921 DC
DescriptorsTemperature, Steels, Marking, Nuts, Mechanical testing, Ferritic steels, Classification systems, Hardness, Grades (quality), Threaded fasteners, Tensile strength, Threads, Fasteners, Mechanical properties of materials, Austenitic steels, Corrosion-resistant steels, Chemical composition, Martensitic steels, Stainless steels, Tensile stress, Designations, Intergranular corrosion
Title in FrenchFixations. Caractéristiques mécaniques des fixations en acier inoxydable résistant à la corrosion Écrous de grades et classes de qualité spécifiés
Title in GermanMechanische Verbindungselemente. Mechanische Eigenschaften von Verbindungselementen aus korrosionsbeständigen nichtrostenden Stählen Muttern mit festgelegten Stahlsorten und Festigkeitsklassen
ISBN978 0 580 92493 4
File Size1.857 MB

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