At Ananka Fasteners Pvt Ltd, we manufacture and supply fasteners certified to ASTM A266. ASTM A266/A266M covers carbon steel forgings for pressure vessel components – shells, tube sheets, hubbed flat heads, nozzles, and flanges – for use under the ASME Boiler and Pressure Vessel Code. Four strength classes (1 through 4) are provided, differing in tensile/yield requirements and heat treatment. Forgings are supplied annealed, normalized, or normalized and tempered.
ASTM A266/A266M covers carbon steel forgings for pressure vessel components – shells, tube sheets, hubbed flat heads, nozzles, and flanges – for use under the ASME Boiler and Pressure Vessel Code. Four strength classes (1 through 4) are provided, differing in tensile/yield requirements and heat treatment. Forgings are supplied annealed, normalized, or normalized and tempered.
| Grade / Class | UNS / Designation | Type / Notes |
|---|---|---|
| Class 1 | K03506 | Carbon steel forging, lowest strength class |
| Class 2 | K03506 | Carbon steel forging, intermediate strength |
| Class 3 | K03506 | Carbon steel forging |
| Class 4 | K03017 | Carbon steel forging |
Minimum mechanical requirements per ASTM A266.
| Grade / Class / Condition | Tensile Strength, min | Yield Strength, min | Elongation, min % | Hardness |
|---|---|---|---|---|
| Class 1 | 60-85 (415-585) | 30 (205) min | 21 | 121-170 HBW typ |
| Class 2 | 70-95 (485-655) | 36 (250) min | 18 | 137-187 HBW typ |
| Class 3 | 65-90 (450-620) | 37.5 (260) min | 17 | 137-187 HBW typ |
| Class 4 | 70-95 (485-655) | 36 (250) min | 18 | 137-187 HBW typ |
| Grade | Key Composition, % |
|---|---|
| Class 1 / 2 | C 0.30 max, Mn 0.40-1.05, P 0.025 max, S 0.025 max, Si 0.15-0.35 |
| Class 3 | C 0.35 max, Mn 0.40-1.05, P 0.025 max, S 0.025 max |
| Class 4 | C 0.30 max, Mn 0.70-1.35, Ni 0.40 max, Cr/Mo residual limits |
Used with the ASME BPVC alongside plate spec ASTM A516 and forging specs A105/A350. International analogues include EN 10222-2 pressure-vessel carbon steel forgings.
For the official ASTM International standards catalogue, see the ASTM International standards listing. This external reference is provided for standards identification; the purchaser should verify the current edition applicable to the order.
We supply ASTM A266 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.
ASTM A266/A266M covers carbon steel forgings for pressure vessel components – shells, tube sheets, hubbed flat heads, nozzles, and flanges – for use under the ASME Boiler and Pressure Vessel Code. Four strength classes (1 through 4) are provided, differing in tensile/yield requirements and heat treatment. Forgings are supplied annealed, normalized, or normalized and tempered.
Ananka Fasteners supplies Class 1, Class 2, Class 3, Class 4 to ASTM A266. 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 ASTM A266 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 ASTM A266 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: ASTM A266 requirement, material grade, fastener type, nominal size, dimensional standard, quantity, inspection requirements and EN 10204 certificate requirements where applicable.
Data compiled per ASTM A266 and industry references; provided for reference only — confirm against the current edition of the standard and certified mill test reports before design use.
