At Ananka Fasteners Pvt Ltd, we manufacture and supply fasteners certified to ISO 3506-2. ISO 3506-2 specifies the mechanical properties of corrosion-resistant stainless steel nuts at ambient temperature, for thread sizes up to M39. Nuts are classified by steel group (A1-A5, C, F) and a property class expressed as a proof-load stress in MPa (e.g., A2-70). Style 1 (full-height) and thin nuts are addressed, with proof loads matched to the corresponding ISO 3506-1 bolt classes.
ISO 3506-2 specifies the mechanical properties of corrosion-resistant stainless steel nuts at ambient temperature, for thread sizes up to M39. Nuts are classified by steel group (A1-A5, C, F) and a property class expressed as a proof-load stress in MPa (e.g., A2-70). Style 1 (full-height) and thin nuts are addressed, with proof loads matched to the corresponding ISO 3506-1 bolt classes.
| Grade / Class | UNS / Designation | Type / Notes |
|---|---|---|
| A2-50 / A4-50 | S30400 / S31600 type | Austenitic nut, soft |
| A2-70 / A4-70 | S30400 / S31600 type | Austenitic nut, cold-worked |
| A2-80 / A4-80 | S30400 / S31600 type | Austenitic nut, strain-hardened |
| C4-70 | Martensitic (416 type) | Free-machining martensitic nut |
| F1-45 | Ferritic (430 type) | Ferritic stainless nut |
Minimum mechanical requirements per ISO 3506-2.
| Grade / Class / Condition | Tensile Strength, min | Yield Strength, min | Elongation, min % | Hardness |
|---|---|---|---|---|
| Class 50 nut | Proof load stress 500 MPa (72.5 ksi) | – | – | – |
| Class 70 nut | Proof load stress 700 MPa (101 ksi) | – | – | – |
| Class 80 nut | Proof load stress 800 MPa (116 ksi) | – | – | – |
| C4-70 nut | Proof load stress 700 MPa (101 ksi) | – | – | – |
| Grade | Key Composition, % |
|---|---|
| A2 | Cr 15-20, Ni 8-19, C 0.10 max (304-type austenitic) |
| A4 | Cr 16-18.5, Ni 10-15, Mo 2-3, C 0.08 max (316-type austenitic) |
Companion to ISO 3506-1 (bolts/screws/studs); adopted as EN ISO 3506-2. Roughly parallels ASTM F594 (inch stainless nuts). A2 ~ AISI 304, A4 ~ AISI 316.
For the official ISO standards catalogue, see the ISO standards listing. This external reference is provided for standards identification; the purchaser should verify the current edition applicable to the order.
We supply ISO 3506-2 fasteners — bolts, screws, studs, nuts and washers as applicable — for energy, petrochemical, marine, structural and general engineering service, in a full range of sizes and finishes.
For technical documentation and quotations, buyers can also review the Ananka Fasteners manufacturing and supply range or contact the team through the fastener enquiry and technical support page.
Ananka Fasteners supplies every lot with full material traceability and third-party testing on request.
ISO 3506-2 specifies the mechanical properties of corrosion-resistant stainless steel nuts at ambient temperature, for thread sizes up to M39. Nuts are classified by steel group (A1-A5, C, F) and a property class expressed as a proof-load stress in MPa (e.g., A2-70). Style 1 (full-height) and thin nuts are addressed, with proof loads matched to the corresponding ISO 3506-1 bolt classes.
Ananka Fasteners supplies A2-50 / A4-50, A2-70 / A4-70, A2-80 / A4-80, C4-70, F1-45 to ISO 3506-2. See the Grades / Classes Covered table above for full details of each grade.
Minimum tensile strength, yield strength, elongation and hardness requirements vary by grade — see the Mechanical Properties table above for the complete breakdown.
We supply ISO 3506-2 fasteners — bolts, screws, studs, nuts and washers as applicable — for energy, petrochemical, marine, structural and general engineering service, in a full range of sizes and finishes.
Yes. For a quotation, provide the required fastener type, grade, nominal size, dimensional standard, quantity and any inspection or certificate requirements.
Need a fastener released to ISO 3506-2 for an industrial project? Send the required fastener type, grade, size, quantity and certification requirements to Ananka Fasteners. Our team can review the requirement and provide technical and commercial information for standard or custom configurations.
Recommended RFQ details: ISO 3506-2 requirement, material grade, fastener type, nominal size, dimensional standard, quantity, inspection requirements and EN 10204 certificate requirements where applicable.
Data compiled per ISO 3506-2 and industry references; provided for reference only — confirm against the current edition of the standard and certified mill test reports before design use.
