At Ananka Fasteners Pvt Ltd, we manufacture and supply fasteners certified to ASTM A320. Alloy and stainless steel bolting materials (bolts, screws, studs, stud bolts) for low-temperature service in pressure vessels, valves, flanges and fittings. Covers quenched-and-tempered alloy grades (L7, L7M, L43) with Charpy impact requirements and solution-treated / strain-hardened austenitic stainless grades (B8, B8M classes 1 and 2).
Alloy and stainless steel bolting materials (bolts, screws, studs, stud bolts) for low-temperature service in pressure vessels, valves, flanges and fittings. Covers quenched-and-tempered alloy grades (L7, L7M, L43) with Charpy impact requirements and solution-treated / strain-hardened austenitic stainless grades (B8, B8M classes 1 and 2).
| Grade / Class | UNS / Designation | Type / Notes |
|---|---|---|
| L7 | AISI 4140/4142 | Q&T alloy steel, impact tested to -150 deg F |
| L7M | AISI 4140 | Q&T alloy, tempered for lower hardness (sour/NACE service) |
| L43 | AISI 4340 | Q&T alloy steel for larger diameters (to 4 in) |
| B8 Class 1 | S30400 (AISI 304) | Carbide solution treated austenitic SS |
| B8 Class 2 | S30400 (AISI 304) | Solution treated + strain hardened |
| B8M Class 1 | S31600 (AISI 316) | Carbide solution treated austenitic SS |
| B8M Class 2 | S31600 (AISI 316) | Solution treated + strain hardened |
| B8T / B8C | S32100 / S34700 | Stabilized 321 / 347 stainless variants |
Minimum mechanical requirements per ASTM A320.
| Grade / Class / Condition | Tensile Strength, min | Yield Strength, min | Elongation, min % | Hardness |
|---|---|---|---|---|
| L7 (to 2-1/2 in) | 125 (860) | 105 (725) | 16 | RA 50% min; Charpy at -150F |
| L7M (to 2-1/2 in) | 100 (690) | 80 (550) | 18 | 235 HBW max; RA 50% |
| L43 (to 4 in) | 125 (860) | 105 (725) | 16 | RA 50% min; Charpy at -150F |
| B8 Class 1 | 75 (515) | 30 (205) | 30 | 223 HBW max; RA 50% |
| B8 Class 2 (to 3/4 in) | 125 (860) | 100 (690) | 12 | 321 HBW max; RA 35% |
| B8M Class 1 | 75 (515) | 30 (205) | 30 | 223 HBW max; RA 50% |
| B8M Class 2 (to 3/4 in) | 110 (760) | 95 (655) | 15 | 321 HBW max; RA 45% |
| Grade | Key Composition, % |
|---|---|
| L7 | C 0.38-0.48, Cr 0.80-1.10, Mo 0.15-0.25, Mn 0.75-1.00 (AISI 4140) |
| L43 | C 0.38-0.43, Ni 1.65-2.00, Cr 0.70-0.90, Mo 0.20-0.30 (AISI 4340) |
| B8 (304) | C 0.08 max, Cr 18-20, Ni 8-11 |
| B8M (316) | C 0.08 max, Cr 16-18, Ni 10-14, Mo 2.00-3.00 |
ASME SA-320 (BPVC Sec. II) is the ASME adoption of ASTM A320 with essentially identical content. Alloy grades typically paired with A194 Gr 4/7 nuts and F436 washers; stainless grades with matching SS nuts (A194 Gr 8/8M).
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 A320 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.
Alloy and stainless steel bolting materials (bolts, screws, studs, stud bolts) for low-temperature service in pressure vessels, valves, flanges and fittings. Covers quenched-and-tempered alloy grades (L7, L7M, L43) with Charpy impact requirements and solution-treated / strain-hardened austenitic stainless grades (B8, B8M classes 1 and 2).
Ananka Fasteners supplies L7, L7M, L43, B8 Class 1, B8 Class 2, B8M Class 1, B8M Class 2, B8T / B8C to ASTM A320. 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 A320 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 A320 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 A320 requirement, material grade, fastener type, nominal size, dimensional standard, quantity, inspection requirements and EN 10204 certificate requirements where applicable.
Data compiled per ASTM A320 and industry references; provided for reference only — confirm against the current edition of the standard and certified mill test reports before design use.
