ASTM A193 Grade B7 Bolts Manufacturer, Supplier & Exporter in Mumbai, India
Jade Alloys holds dual certification as a manufacturer, supplier and exporter of ASTM A193 Grade B7 Bolts, operating out of Mumbai, India. We’ve built long-standing relationships with refineries, power plants, petrochemical EPC contractors and procurement teams spanning the USA, Middle East, Europe and Southeast Asia. Every B7 fastener we supply is made from AISI 4140, 4142 or 4145 chromium-molybdenum alloy steel, each batch goes through quenching and tempering to meet the exact requirements of ASTM A193 and ASME SA193. You can find a detailed breakdown of what that standard covers on our ASTM A193 standard overview page.
ASTM A193 B7 is the most widely specified bolting grade for high-temperature and high-pressure service pressure vessels, flanges, valves and fittings across oil & gas, petrochemical and power generation. Pair them with ASTM A194 Grade 2H Heavy Hex Nuts for a code-compliant bolting assembly. Browse our complete range of Alloy Steel Fasteners for all related grades.
Why Engineers Specify ASTM A193 B7 Bolts
- Min. tensile strength: 125 ksi (860 MPa) for diameters ≤ 2½″
- Service range: –50°C to +482°C (–58°F to +900°F)
- Chromium-molybdenum alloy retains strength at elevated temperatures
- Max hardness 35 HRC / 321 HBW — controlled to prevent brittle fracture
- NACE MR0175 / ISO 15156 & NACE MR0103 compliance available
- Dual certified ASTM & ASME — PED 97/23/EC for EU supply
ASTM A193 Grade B7 Bolts Specification Overview
| Property | Details |
|---|---|
| Standard | ASTM A193 / ASME SA193 |
| Grade | B7 (also available: B7M, B16, B8, B8M) |
| Material / Alloy | Chromium-Molybdenum Alloy Steel — AISI 4140, 4142, 4145 |
| Heat Treatment | Quenched & Tempered — min. tempering temp. 1150°F (620°C) |
| Bolt Dimensions Standard | ASME B18.2.1, ASME B18.3 |
| Thread Configuration | ASME B1.1 (2A/3A) — UNC/UNF; ASME B1.13M 6h — Metric Coarse |
| Thread Note (Diameter > 1″) | 8 TPI (threads per inch) for traditional applications |
| Size Range — Inch | ¼″ to 4″; custom to 7″ |
| Size Range — Metric | M6 to M180 |
| Certification | Dual Certified ASTM & ASME; PED 97/23/EC; Merkblatt AD 2000 W2 |
| NACE Compliance | NACE MR0103; NACE MR0175 / ISO 15156 |
| Recommended Nut | ASTM A194 Grade 2H (standard); A194 Grade 2HM (sour service) |
| Operating Temp Range | –50°C to +482°C (–58°F to +900°F) |
| Product Origin | Made in India — Mumbai |
Request a Free Quote for ASTM A193 B7 Bolts
✔ Fast response within 4 business hours
✔ Competitive ex-works pricing from Mumbai
✔ All sizes, grades and certifications available
📞 +91 9987685906 | ✉ sales@jadealloys.com
ASTM A193 Grades
Types of ASTM A193 Grade B7 Fasteners
Also available: Threaded Rods, Double End Studs, Square Head Bolts, J-Bolts and custom profiles. See our Alloy Steel Bolts category for all grades.
ASTM A193 Grade B7 Fasteners Chemical Composition
Grade B7 fasteners are produced from chromium-molybdenum alloy steel. The chromium content provides corrosion resistance and hardenability, while molybdenum enhances strength at elevated temperatures. The following composition limits apply:
| Element | Symbol | Min (%) | Max (%) |
|---|---|---|---|
| Carbon | C | 0.37 | 0.49 |
| Manganese | Mn | 0.65 | 1.10 |
| Phosphorus | P | — | 0.035 |
| Sulfur | S | — | 0.040 |
| Silicon | Si | 0.15 | 0.35 |
| Chromium | Cr | 0.75 | 1.20 |
| Molybdenum | Mo | 0.15 | 0.25 |
Source: ASTM A193 Standard Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service.
ASTM A193 Grade B7 Mechanical Properties
Mechanical properties vary with diameter. For a full grade comparison by tensile class, see our Bolt Tensile Strength Chart blog.
Inch Sizes
| Diameter (in) | Min Temp (°F) | Tensile Min | Yield Min (0.2%) | Elong Min | Red. of Area | Hardness Max |
|---|---|---|---|---|---|---|
| ≤ 2½″ | 1100 | 125 ksi / 860 MPa | 105 ksi / 725 MPa | 16% | 50% | 321 HBW / 35 HRC |
| 2½″ to 4″ | 1100 | 115 ksi / 795 MPa | 95 ksi / 655 MPa | 16% | 50% | 321 HBW / 35 HRC |
| 4″ to 7″ | 1100 | 100 ksi / 690 MPa | 75 ksi / 515 MPa | 18% | 50% | 321 HBW / 35 HRC |
Metric Sizes
| Diameter (mm) | Min Temp (°C) | Tensile Min (MPa) | Yield Min (MPa) | Elong Min | Red. of Area | Hardness Max |
| M64 and under | 593 | 860 | 720 | 16% | 50% | 321 HBW / 35 HRC |
| Over M64 to M100 | 593 | 795 | 655 | 16% | 50% | 321 HBW / 35 HRC |
| Over M100 to M180 | 593 | 690 | 515 | 18% | 50% | 321 HBW / 35 HRC |
ASTM A193 B7 vs B7M — Choosing the Right Grade
Both grades use the same Cr-Mo alloy base, but B7M is heat-treated to a lower maximum hardness specifically for sour (H₂S) service compliance under NACE MR0175 / ISO 15156.
| Property | Grade B7 | Grade B7M |
|---|---|---|
| Base Material | AISI 4140/4142/4145 | AISI 4140/4142/4145 |
| Max Hardness | 35 HRC / 321 HBW | 22 HRC / 235 HBW |
| Min Tensile (≤2½″) | 125 ksi (860 MPa) | 100 ksi (690 MPa) |
| Sour Service (NACE MR0175) | Not qualified | Fully qualified |
| Paired Nut Grade | A194 Gr. 2H | A194 Gr. 2HM |
| Typical Application | General high-press / high-temp | Wet H₂S / sour crude / acid gas |
Specify B7M when the bolting environment contains wet H₂S. Paired with ASTM A194 Grade 2H Nuts for standard service or A194 2HM for sour environments. See also our ASTM A194 standard page.
ASTM A193 B7 vs B16 — When to Upgrade to Vanadium Grade
For service above ~482°C (900°F) particularly steam turbines and boiler bolting engineers specify ASTM A193 B16 Bolts (vanadium-enhanced Cr-Mo). B7 remains the workhorse for standard petrochemical and refinery bolting.
| Property | Grade B7 | Grade B16 |
|---|---|---|
| Alloying Element | Cr-Mo (no vanadium) | Cr-Mo + 0.25–0.35% Vanadium |
| Min Tensile (≤2½″) | 125 ksi (860 MPa) | 125 ksi (860 MPa) |
| Max Service Temp | ~482°C (900°F) | ~593°C (1100°F) |
| Creep Resistance | Moderate | Superior |
| Typical Application | Standard high-press/temp | Ultra-high-temp steam, boilers, turbines |
Temperature & Pressure Service Range
|
Operating Temperature: –50°C to +482°C (–58°F to +900°F) For below –50°C: Specify ASTM A320 L7 Bolts (Charpy impact tested) For above +482°C: Specify ASTM A193 B16 (vanadium grade for creep resistance) Min. Tempering Temp: 620°C (1150°F) per ASTM A193 Design Pressure: Suitable for ASME B16.5 / B16.47 rated flanges and pressure vessels |
For sub-zero cryogenic applications, see ASTM A320 L7 Bolts. For an in-depth comparison, read our blog: ASTM A193 vs A320 — High Temperature vs Cryogenic Bolting.
ASTM A193 B7 Heavy Hex Bolt Dimensions (Inch — ASME B18.2.1)
For a printable bolt weight reference, see our Bolts Weight Chart and the Bolt Weight Chart blog (M6–M64). All dimensions in inches.
| Dia (D) | Body Max | Body Min | Flats Max | Flats Min | Corners Max | Corners Min | Head H Max | Head H Min | Thread <6″ | Thread >6″ |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 0.515 | 0.482 | 0.875 | 0.850 | 1.010 | 0.969 | 0.364 | 0.302 | 1.25″ | 1.50″ |
| 5/8″ | 0.642 | 0.605 | 1.062 | 1.031 | 1.227 | 1.175 | 0.444 | 0.378 | 1.50″ | 1.75″ |
| 3/4″ | 0.768 | 0.729 | 1.250 | 1.212 | 1.443 | 1.383 | 0.524 | 0.455 | 1.75″ | 2.00″ |
| 7/8″ | 0.895 | 0.852 | 1.438 | 1.394 | 1.660 | 1.589 | 0.604 | 0.531 | 2.00″ | 2.25″ |
| 1″ | 1.022 | 0.976 | 1.625 | 1.575 | 1.876 | 1.796 | 0.700 | 0.591 | 2.25″ | 2.50″ |
| 1-1/4″ | 1.277 | 1.223 | 2.000 | 1.938 | 2.309 | 2.209 | 0.876 | 0.749 | 2.75″ | 3.00″ |
| 1-1/2″ | 1.531 | 1.470 | 2.375 | 2.300 | 2.742 | 2.622 | 1.036 | 0.902 | 3.25″ | 3.50″ |
| 2″ | 2.039 | 1.964 | 3.125 | 3.025 | 3.608 | 3.449 | 1.388 | 1.175 | 4.25″ | 4.50″ |
| 2-1/2″ | 2.559 | 2.461 | 3.875 | 3.750 | 4.474 | 4.275 | 1.708 | 1.479 | 5.25″ | 5.50″ |
| 3″ | 3.081 | 2.961 | 4.625 | 4.475 | 5.340 | 5.102 | 2.060 | 1.815 | 6.25″ | 6.50″ |
ASTM A193 B7 Hex Bolt Dimensions (Metric — mm)
| Size | D Max | D Min | H Max | H Min | F Max | F Min | C Max | C Min |
|---|---|---|---|---|---|---|---|---|
| M10 | 10.00 | 9.78 | 6.63 | 6.17 | 17.00 | 15.73 | 18.48 | 17.77 |
| M12 | 12.00 | 11.73 | 7.76 | 4.24 | 19.00 | 17.73 | 20.78 | 20.03 |
| M16 | 16.00 | 15.73 | 10.32 | 9.68 | 24.00 | 23.67 | 27.71 | 26.75 |
| M20 | 20.00 | 19.67 | 12.88 | 12.12 | 30.00 | 29.16 | 34.64 | 32.95 |
| M24 | 24.00 | 23.67 | 15.44 | 14.56 | 36.00 | 35.00 | 41.57 | 39.55 |
| M30 | 30.00 | 29.67 | 19.48 | 17.92 | 46.00 | 45.00 | 53.12 | 50.85 |
| M36 | 36.00 | 35.61 | 23.38 | 21.63 | 55.00 | 53.80 | 63.51 | 60.79 |
| M48 | 48.00 | 47.38 | 31.07 | 28.93 | 75.00 | 72.60 | 86.60 | 82.76 |
| M64 | 64.00 | 63.26 | 41.32 | 38.68 | 95.00 | 91.80 | 109.70 | 104.65 |
| M80 | 80.00 | 79.26 | 51.58 | 48.42 | 115.00 | 111.00 | 132.72 | 126.54 |
| M100 | 100.00 | 99.13 | 63.90 | 60.10 | 145.00 | 140.00 | 167.43 | 159.60 |
ASTM A193 B7 Torque Chart With A194 Grade 2H Nuts
Reference torque values with ASTM A194 Grade 2H Nuts and K = 0.15 (standard lubricant). Always verify against ASME PCC-1 or your project bolt tightening specification.
| Bolt Size | TPI | Torque Dry (ft-lbs) | Torque Lubricated (ft-lbs) | Torque Lubricated (Nm) | Proof Load (lbs) | Clamp Load (lbs) |
|---|---|---|---|---|---|---|
| 1/4″ | 20 | 9 | 7 | 9 | 3,350 | 2,513 |
| 3/8″ | 16 | 32 | 24 | 33 | 8,150 | 6,113 |
| 1/2″ | 13 | 77 | 58 | 79 | 14,900 | 11,175 |
| 5/8″ | 11 | 151 | 113 | 153 | 23,750 | 17,813 |
| 3/4″ | 10 | 267 | 200 | 271 | 35,050 | 26,288 |
| 7/8″ | 9 | 432 | 324 | 439 | 48,500 | 36,375 |
| 1″ | 8 | 648 | 486 | 659 | 63,650 | 47,738 |
| 1-1/4″ | 8 | 1,293 | 970 | 1,315 | — | — |
| 1-1/2″ | 8 | 2,299 | 1,725 | 2,339 | — | — |
| 2″ | 8 | 5,750 | 4,313 | 5,849 | — | — |
| 2-1/2″ | 8 | 11,340 | 8,505 | 11,534 | — | — |
⚠️ Reference values only. Consult ASME PCC-1 or applicable project spec for final torque requirements.
A193 B7 Stud Bolt Weight Chart (lbs/piece)
Approximate weights for plain (uncoated) double-end stud bolts. Hot-dip galvanizing adds ~3–5%. Full weight tables at our Bolts Weight Chart page and Bolt Weight Chart blog.
| Length | 1/2″ | 3/4″ | 1″ | 1-1/4″ | 1-1/2″ |
|---|---|---|---|---|---|
| 3″ | 0.13 | 0.30 | 0.55 | 0.90 | 1.33 |
| 4″ | 0.17 | 0.40 | 0.74 | 1.20 | 1.77 |
| 5″ | 0.22 | 0.51 | 0.93 | 1.50 | 2.22 |
| 6″ | 0.26 | 0.61 | 1.11 | 1.80 | 2.66 |
| 7″ | 0.30 | 0.71 | 1.30 | 2.10 | 3.10 |
Compatible Nuts & Washers for ASTM A193 B7 Bolts
| Nut Grade | Service Condition | Standard | Notes |
|---|---|---|---|
| ASTM A194 Grade 2H | General high-pressure/high-temp | ASTM A194 | Most common pairing with B7 |
| ASTM A194 Grade 2HM | Sour service H₂S (with B7M) | ASTM A194 | Lower hardness — NACE MR0175 compliant |
| ASTM A194 Grade 4 | High-temp service >900°F | ASTM A194 | Mo alloy; for extreme temps |
| ASTM A194 Grade 7 | Low-temp service (with A320 L7) | ASTM A194 | Quenched & tempered alloy steel |
| ASTM A563 Grade DH | General purpose alternative | ASTM A563 | Heavy hex; where A194-2H unavailable |
Washer Recommendation: ASTM F436 Type 1 hardened steel washers under ASME PCC-1.
Available Surface Coatings & Finishes
For a full comparison of bolt coating types and corrosion protection levels, read: Types of Fastener Coatings and Galvanized Bolts vs Stainless Steel Bolts.
| Coating / Finish | Standard / Process | Best Application |
|---|---|---|
| Plain (Self-Colour) | No coating — natural steel | Dry / indoor; apply bolt lubricant at site |
| Hot-Dip Galvanized | ASTM A153 / ISO 1461 | Outdoor / marine; significant corrosion protection |
| PTFE / Xylan Coated | ASTM B117 salt-spray tested | Chemical environments; consistent assembly torque |
| Zinc-Nickel Plated | ASTM B633 | Atmospheric corrosion; marine and industrial use |
| Black Phosphate | MIL-DTL-16232 | Assembly lubrication; mild corrosion protection |
| Ceramic Coated | Project-specific | Ultra-high-temp furnace and exhaust applications |
Quality Testing & Certifications
Every batch of ASTM A193 B7 Bolts from Jade Alloys is tested before dispatch. View our Quality Policy and Certificates page for Mill Test Certificate samples and inspection accreditation.
| Test / Inspection | Method / Standard | Acceptance Criteria |
|---|---|---|
| Tensile & Yield Test | ASTM A370 — Universal Testing Machine | Min. tensile & yield per diameter range |
| Hardness Test | Rockwell HRC / Brinell HBW — ASTM E18 / E10 | Max 35 HRC / 321 HBW |
| Chemical Analysis (PMI) | OES / XRF Spectrometry | Within ASTM A193 composition limits |
| Dimensional Inspection | Vernier, micrometer, CMM, Go/No-Go gauges | Per ASME B18.2.1 / B18.3 tolerances |
| Thread Gauging | ASME B1.1 thread gauges (Go/No-Go) | Class 2A / 3A as specified |
| Charpy Impact Test | ASTM E23 (on request) | Per ASTM A320 if low-temp service required |
| MPI / UT | ASTM E709 / ASTM A388 (on request) | No surface or sub-surface defects |
Certifications: Dual Certified ASTM & ASME | PED 97/23/EC | AD 2000 W2 | NACE MR0175 / MR0103 | MTC EN 10204 3.1 standard; 3.2 on request | TPI: TUV, BV, SGS, Lloyds, Intertek
ASTM A193 B7 Bolts Inventory
ASTM A193 B7 Bolts
ASTM A193 B7 Stud Bolts
ASTM A193 B7 Hex Bolts
Applications of ASTM A193 B7 Bolts by Industry
Read Benefits of Using Alloy Steel Fasteners in Industrial Applications for an in-depth look at why Cr-Mo B7 bolts outperform carbon steel fasteners in demanding service.
| Industry | Specific Applications |
|---|---|
| Oil & Gas Upstream | Wellhead flanges, BOP assemblies, Christmas tree components, pipeline flanges |
| Petrochemical & Refining | Pressure vessel bolting, heat exchanger flanges, reactor closures, pump casings |
| Power Generation | Steam turbine casings, boiler drum flanges, high-pressure valve bonnet bolting |
| Chemical Processing | Reactor flanges, agitator shaft retention, pressure system bolting |
| Heavy Construction | Structural bolting in industrial frames, high-load anchor bolt systems |
| Shipbuilding & Marine | Engine room pressure connections, exhaust manifolds, high-temp piping |
Manufacturing Process at Jade Alloys, Mumbai
| Step | Stage | Description |
|---|---|---|
| 1 | Raw Material | Mill-certified AISI 4140/4142/4145 bar stock — traceable heat numbers |
| 2 | Forming | Cold heading or hot forging depending on diameter and fastener type |
| 3 | Heat Treatment | Austenitizing → liquid quench → temper at min. 620°C (1150°F) |
| 4 | Threading | Thread rolling / cutting to ASME B1.1 (UNC/UNF) or B1.13M (metric) |
| 5 | Surface Treatment | Plain, HDG, PTFE, Zinc-Nickel, Black Phosphate as specified |
| 6 | Inspection | 100% dimensional verification — calibrated gauges, CMM, thread gauges |
| 7 | Testing | Tensile, hardness, PMI chemical analysis, Charpy impact on request |
| 8 | TPI / MTC | Third-party inspection; MTC per EN 10204 3.1 / 3.2 issued |
| 9 | Packing & Dispatch | Rust-preventive packing; ISPM-15 fumigated export crating |
Packaging & Global Export from Mumbai
Jade Alloys ships ASTM A193 B7 Bolts to 35+ countries. Packaging complies with ISPM-15 fumigation requirements. Export documents: commercial invoice, packing list, certificate of origin, MTC and fumigation certificate.
Why Choose Jade Alloys for ASTM A193 B7 Bolt Manufacturer in Mumbai?
- 20+ years manufacturing experience in alloy steel fasteners
- Direct manufacturer — no middlemen; competitive ex-works pricing
- Ready stock ¼″ to 4″ (M6 to M100) for urgent project requirements
- Dual-certified ASTM & ASME; PED compliant for European supply
- Third-party inspection at our Mumbai facility by customer-nominated bodies
- Custom sizes, thread forms and coatings in 5–15 working days
- Full material traceability — heat numbers on every MTC
- Mercury-free & radioactive contamination-free certification available
- Established export track record — 35+ countries, 6 continents
Frequently Asked Questions — ASTM A193 B7 Bolts
Related Products
ASTM A193 Grade B7 Bolts are the proven, industry-standard Cr-Mo alloy fastening solution for high-temperature and high-pressure pressure equipment. Jade Alloys, Mumbai, supplies the complete range of B7 Stud Bolts, Heavy Hex Bolts, Anchor Bolts and Threaded Rods dual-certified, ready-stocked and export-ready. For a free quote, detailed MTC samples or technical support, contact our team today.
Request a Free Quote for ASTM A193 B7 Bolts
- Fast response within 4 business hours
- Competitive ex-works pricing from Mumbai
- All sizes, grades and certifications available
📞 +91 9987685906 | ✉ sales@jadealloys.com
