At Ananka Fasteners Pvt Ltd, we manufacture and supply fasteners certified to BS 4190. British Standard for ISO metric black hexagon bolts, screws and nuts. Specifies dimensions, tolerances and mechanical property classes for general-purpose (black, non-precision) hexagon fasteners in the ISO metric thread series, M5 to M68. Mechanical property classes follow ISO 898-1 (bolts/screws) and ISO 898-2 (nuts). Input category ‘Nuts’ understates scope – covers bolts, screws AND nuts.
British Standard for ISO metric black hexagon bolts, screws and nuts. Specifies dimensions, tolerances and mechanical property classes for general-purpose (black, non-precision) hexagon fasteners in the ISO metric thread series, M5 to M68. Mechanical property classes follow ISO 898-1 (bolts/screws) and ISO 898-2 (nuts). Input category ‘Nuts’ understates scope – covers bolts, screws AND nuts.
| Grade / Class | UNS / Designation | Type / Notes |
|---|---|---|
| Class 4.6 | Low/medium carbon steel | Black hex bolts/screws |
| Class 4.8 | Carbon steel | Black hex screws (small sizes) |
| Class 8.8 | Carbon or C-boron steel, Q&T | Black hex bolts/screws |
| Nut class 4 / 5 / 8 | Carbon steel | Matched black hex nuts |
Minimum mechanical requirements per BS 4190.
| Grade / Class / Condition | Tensile Strength, min | Yield Strength, min | Elongation, min % | Hardness |
|---|---|---|---|---|
| Class 4.6 | 400 MPa (58 ksi) | 240 MPa (35 ksi) | 22 | 120-220 HV |
| Class 4.8 | 420 MPa (61 ksi) | 340 MPa (49 ksi) | 14 | 130-220 HV |
| Class 8.8 (<=M16) | 800 MPa (116 ksi) | 640 MPa (93 ksi) | 12 | 250-320 HV |
| Class 8.8 (>M16) | 830 MPa (120 ksi) | 660 MPa (96 ksi) | 12 | 255-336 HV |
| Nut class 5 | Proof 500 MPa (73 ksi) | n/a (nut) | n/a | <=272 HV |
| Nut class 8 | Proof 800 MPa (116 ksi) | n/a (nut) | n/a | <=302 HV |
| Grade | Key Composition, % |
|---|---|
| Class 4.6 | Low/medium carbon steel; C 0.55 max, P/S controlled |
| Class 4.8 | Carbon steel, cold worked or as processed |
| Class 8.8 | Carbon or carbon-boron steel, quenched & tempered |
Black (non-precision) counterpart to BS 3692; property classes per ISO 898-1/898-2; aligns with EN ISO 4014/4016/4017/4032/4034.
For the official BSI standards catalogue, see the BSI standards listing. This external reference is provided for standards identification; the purchaser should verify the current edition applicable to the order.
We supply BS 4190 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.
British Standard for ISO metric black hexagon bolts, screws and nuts. Specifies dimensions, tolerances and mechanical property classes for general-purpose (black, non-precision) hexagon fasteners in the ISO metric thread series, M5 to M68. Mechanical property classes follow ISO 898-1 (bolts/screws) and ISO 898-2 (nuts). Input category ‘Nuts’ understates scope – covers bolts, screws AND nuts.
Ananka Fasteners supplies Class 4.6, Class 4.8, Class 8.8, Nut class 4 / 5 / 8 to BS 4190. 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 BS 4190 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 BS 4190 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: BS 4190 requirement, material grade, fastener type, nominal size, dimensional standard, quantity, inspection requirements and EN 10204 certificate requirements where applicable.
Data compiled per BS 4190 and industry references; provided for reference only — confirm against the current edition of the standard and certified mill test reports before design use.
