Garde B7 fastener is a very suitable choice for the petroleum and chemical industries. They come with the ASTM standard and are designed for high temperature and high pressure applications like pressure vessels, valves, flanges, and fittings. They are also available in different standards such as UNC thread pitches, diameters over one inch typically use 8 threads per inch (tpi) for traditional uses.
For a quick quote on A193 Grade B7 Bolts, reach out to us at Contact Us page.
ASTM A193 B7 Bolts, ASTM A193 Grade B7 Stud Bolts, B7 Fasteners and Nuts, A193 Gr. B7 Threaded Rod Manufacturer and Supplier
Jade Special Metals is among the top manufacturers and distributors of ASTM A193 B7 Bolts, ASTM A193 Grade B7 Stud Bolts and A193 Gr. B7 Threaded Rod and provides certified fasteners to its customers worldwide. The most commonly used grade that is specified by ASTM A193 is grade B7, which is used in alloy steel and stainless steel bolting where there is service in high temperatures or high pressures.
B7 fasteners are made of chromium-molybdenum alloy steel (usually AISI 4140, 4142 or 4145) quenched and tempered to a minimum tempering temperature of 1150O C. Such heat treatment provides the required combination of high tensile strength, high ductility and impact toughness. The brittle nature is controlled by the maximum Rockwell hardness of 35 HRC (321 HBW) without affecting the strength in a wide service temperature of -50 to 900 0 C -45 to 482.
A193 B7 fasteners are used to prefer bolting material of pressure vessel, flanges, valves, and fittings in petroleum, petrochemical, power generation as well as in heavy construction industries. They are normally combined with ASTM A194 Grade 2H heavy hex nuts.
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Bolts Weight Chart
Table of Content
- Types of A193 Grade B7 Fasteners
- ASTM A193 Grade B7 Stainless Steel Bolts Specification
- ASTM A193 Grade B7 Fasteners Chemical Composition
- ASTM A193 Grade B7 Bolts Mechanical Properties
- A193 B7 vs B7M — What’s the Difference?
- SA193 Grade B7 Heavy Hex Bolts Dimension
- Dimension of ASTM A193 Grade B7 Bolts
- A193 B7 Studs Size Chart
- ASTM A193 Grade B7 Torque Chart
- ASTM A193 Gr B7 Stud Bolt Weight
- ASTM A193 B7 Bolts Inventory
- Applications of ASTM A193 B7 Bolts
Types of A193 Grade B7 Fasteners
A193 B7 Stud Bolts
A193 B7 Hex Bolts
A193 B7 Anchor Bolts
A193 B7 Threaded Rods
A193 B7 Socket Head Cap Screws
A193 B7 Heavy Hex Bolts
A193 B7 U-Bolts
A193 B7 Washers
ASTM A193 Grade B7 Stainless Steel Bolts Specification
All A193 B7 fasteners supplied by Jade Special Metals are dual certified to ASTM and ASME codes and manufactured to the following specifications:
| Property | Details |
|---|---|
| Standard | ASTM A193 / ASME SA193 |
| Grade | B7 (also available: B7M, B16, B8, B8M) |
| Material | Chromium-Molybdenum Alloy Steel — AISI 4140, 4142, 4145 |
| Bolt Dimensions Standard | ASME B18.2.1, ASME B18.3 |
| Thread Configuration | ASME B1.1 2A/3A — Inch Unified (UNC/UNF); ASME B1.13M 6h — Metric Coarse |
| Thread Note | Diameters ≤1″: standard UNC pitch; Diameters >1″: 8 TPI (threads per inch) |
| Size Range | ¼” to 4″ (6 mm to 100 mm); custom sizes available |
| Length | As per requirement or ASME standards |
| Heat Treatment | Quenched & Tempered, min. tempering temperature 1150°F (620°C) |
| Certification | Dual Certified ASTM & ASME Codes |
| Additional Certifications | PED 97/23/EC, Merkblatt AD 2000 W2 |
| Compliance | NACE MR0103, NACE MR0175 / ISO 15156 |
| Mandatory Requirements | Free from Mercury & Radioactive Contamination |
| Melt Origin | South America / East Europe / Japan / Korea |
| Product Origin | Made in India |
| Recommended Nut Pairing | ASTM A194 Grade 2H (standard); A194 Grade 2HM (sour service) |
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 Bolts Mechanical Properties
The mechanical properties of A193 B7 bolts vary with diameter. Larger diameters require higher tempering temperatures and result in lower minimum tensile/yield strength values:
| Diameter Range | Min. Tensile Strength | Min. Yield Strength (0.2% Proof) | Min. Elongation (2″) | Min. Reduction of Area | Max. Hardness |
|---|---|---|---|---|---|
| ≤ 2½ in (≤ 65 mm) | 125 ksi / 860 MPa | 105 ksi / 725 MPa | 16% | 50% | 321 HBW / 35 HRC |
| 2½ in to 4 in (65–100 mm) | 115 ksi / 795 MPa | 95 ksi / 655 MPa | 16% | 50% | 321 HBW / 35 HRC |
| 4 in to 7 in (100–180 mm) | 100 ksi / 690 MPa | 75 ksi / 515 MPa | 18% | 50% | 321 HBW / 35 HRC |
A193 B7 vs B7M — What's the Difference?
A common source of confusion is the difference between Grade B7 and Grade B7M. Both are made from the same chromium-molybdenum alloy steel, but they are optimized for different service environments:
| Property | Grade B7 | Grade B7M |
|---|---|---|
| Base Material | Cr-Mo Alloy (4140/4142/4145) | Cr-Mo Alloy (4140/4142/4145) |
| Max. Hardness | 35 HRC / 321 HBW | 22 HRC / 235 HBW |
| Min. Tensile Strength (≤2½”) | 125 ksi (860 MPa) | 100 ksi (690 MPa) |
| Sour Service (NACE MR0175) | Not qualified (without hardness control) | Qualified for H₂S environments |
| Typical Application | General high-pressure / high-temp service | Wet H₂S / sour crude / acid gas service |
| Paired Nut | A194 Gr. 2H | A194 Gr. 2HM |
When to choose B7M: Specify Grade B7M when the service environment contains wet hydrogen sulfide (H₂S), which can cause sulfide stress cracking (SSC) in high-hardness steel. B7M’s controlled hardness (max. 22 HRC) prevents SSC under NACE MR0175 / ISO 15156 requirements.
SA193 Grade B7 Heavy Hex Bolts Dimension
| NOMINAL SIZE (D) | BODY DIAMETER | HEAD THICKNEASTM A193 | ACROASTM A193 THE FLATS | ACROASTM A193 CORNERS | ||||
|---|---|---|---|---|---|---|---|---|
| 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 |
| m14 | 14.00 | 13.73 | 9.09 | 8.51 | 22.00 | 20.67 | 24.25 | 23.35 |
| m80 | 80.00 | 79.26 | 51.58 | 48.42 | 115.00 | 111.00 | 132.72 | 126.54 |
| 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 |
| m48 | 48.00 | 47.38 | 31.07 | 28.93 | 75.00 | 72.60 | 86.60 | 82.76 |
| 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 |
| m42 | 42.00 | 41.38 | 26.97 | 25.03 | 65.00 | 62.90 | 75.06 | 71.71 |
| m56 | 56.00 | 55.26 | 36.2 | 33.80 | 85.00 | 82.20 | 98.15 | 93.71 |
| m64 | 64.00 | 63.26 | 41.32 | 38.68 | 95.00 | 91.80 | 109.70 | 104.65 |
| m72 | 72.00 | 71.26 | 46.45 | 43.55 | 105.00 | 101.40 | 121.24 | 115.60 |
| m12 | 12.00 | 11.73 | 7.76 | 4.24 | 19.00 | 17.73 | 20.78 | 20.03 |
| m90 | 90.00 | 89.13 | 57.74 | 54.26 | 130.00 | 125.50 | 150.11 | 143.07 |
| m100 | 90.00 | 99.13 | 63.9 | 60.10 | 145.00 | 140.00 | 167.43 | 159.60 |
Dimension of ASTM A193 Grade B7 Bolts
| Diameter (D) | Body Diameter (D) | Across the Flats (F) | Across the Corners © | Head Height (H) | Thread Lengths (T) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| MAX | MIN | MAX | MIN | MAX | MIN | MAX | MIN | < 6” | > 6” | |
| 1 | 1.022 | 0.976 | 1.625 | 1.575 | 1.876 | 1.796 | 0.7 | 0.591 | 2.25 | 2.5 |
| 5/8 | 0.642 | 0.605 | 1.062 | 1.031 | 1.227 | 1.175 | 0.444 | 0.378 | 1.5 | 1.75 |
| 3/4 | 0.768 | 0.729 | 1.25 | 1.212 | 1.443 | 1.383 | 0.524 | 0.455 | 1.75 | 2 |
| 1/2 | 0.515 | 0.482 | 0.875 | 0.85 | 1.01 | 0.969 | 0.364 | 0.302 | 1.25 | 1.5 |
| 7/8 | 0.895 | 0.852 | 1.438 | 1.394 | 1.66 | 1.589 | 0.604 | 0.531 | 2 | 2.25 |
| 1 1/8 | 1.149 | 1.098 | 1.812 | 1.756 | 2.093 | 2.002 | 0.78 | 0.658 | 2.5 | 2.75 |
| 1 1/4 | 1.277 | 1.223 | 2 | 1.938 | 2.309 | 2.209 | 0.876 | 0.749 | 2.75 | 3 |
| 1 3/4 | 1.785 | 1.716 | 2.75 | 2.662 | 3.175 | 3.035 | 1.196 | 1.054 | 3.75 | 4 |
| 1 3/8 | 1.404 | 1.345 | 2.188 | 2.119 | 2.526 | 2.416 | 0.94 | 0.81 | 3 | 3.25 |
| 1 1/2 | 1.531 | 1.47 | 2.375 | 2.3 | 2.742 | 2.622 | 1.036 | 0.902 | 3.25 | 3.5 |
| 2 3/4 | 2.827 | 2.711 | 4.25 | 4.112 | 4.907 | 4.688 | 1.869 | 1.632 | 5.75 | 6 |
| 2 | 2.039 | 1.964 | 3.125 | 3.025 | 3.608 | 3.449 | 1.388 | 1.175 | 4.25 | 4.5 |
| 2 1/4 | 2.305 | 2.214 | 3.5 | 3.388 | 4.041 | 3.862 | 1.548 | 1.327 | 4.75 | 5 |
| 2 1/2 | 2.559 | 2.461 | 3.875 | 3.75 | 4.474 | 4.275 | 1.708 | 1.479 | 5.25 | 5.5 |
| 3 | 3.081 | 2.961 | 4.625 | 4.475 | 5.34 | 5.102 | 2.06 | 1.815 | 6.25 | 6. |
A193 B7 Studs Size Chart
Check the weight and dimensions of A193 B7 Hex Bolts and ASTM A193 Grade B7 Stud Bolts
| Nominal Basic | Size or Screw | Body | D Diameter | Head | A Diameter | Head | H Height | $ Head Side Height | J Hex Socket Size | T Key Engagmt | G Wall Thkns | K Chamfer or Radius |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diameter | Max | Min | Max | Min | Max | Min | Max | Nominal | Min | Min | Max | |
| 0 | 0.0600 | 0.0600 | 0.0568 | 0.096 | 0.091 | 0.060 | 0.057 | 0.054 | 0.050 | 0.025 | 0.020 | 0.003 |
| 1 | 0.0730 | 0.0730 | 0.0695 | 0.118 | 0.112 | 0.073 | 0.070 | 0.066 | 1/16 0.062 | 0.031 | 0.025 | 0.003 |
| 2 | 0.0860 | 0.0860 | 0.0822 | 0.140 | 0.134 | 0.086 | 0.083 | 0.077 | 5/64 0.078 | 0.038 | 0.029 | 0.003 |
| 3 | 0.0990 | 0.0990 | 0.0949 | 0.161 | 0.154 | 0.099 | 0.095 | 0.089 | 5/64 0.078 | 0.044 | 0.034 | 0.003 |
| 4 | 0.1120 | 0.1120 | 0.1075 | 0.183 | 0.176 | 0.112 | 0.108 | 0.101 | 3/32 0.094 | 0.051 | 0.038 | 0.005 |
| 5 | 0.1250 | 0.1250 | 0.1202 | 0.205 | 0.198 | 0.125 | 0.121 | 0.112 | 3/32 0.094 | 0.057 | 0.043 | 0.005 |
| 6 | 0.1380 | 0.1380 | 0.1329 | 0.226 | 0.218 | 0.138 | 0.134 | 0.124 | 7/64 0.109 | 0.064 | 0.047 | 0.005 |
| 8 | 0.1640 | 0.1640 | 0.1585 | 0.270 | 0.262 | 0.164 | 0.159 | 0.148 | 9/64 0.141 | 0.077 | 0.056 | 0.005 |
| 10 | 0.1900 | 0.1900 | 0.1840 | 0.312 | 0.303 | 0.190 | 0.185 | 0.171 | 5/32 0.156 | 0.090 | 0.065 | 0.005 |
| 1/4 | 0.2500 | 0.2500 | 0.2435 | 0.375 | 0.365 | 0.250 | 0.244 | 0.225 | 3/16 0.188 | 0.120 | 0.095 | 0.008 |
| 5/16 | 0.3125 | 0.3125 | 0.3053 | 0.469 | 0.457 | 0.312 | 0.306 | 0.281 | 1/4 0.250 | 0.151 | 0.119 | 0.008 |
| 3/8 | 0.3750 | 0.3750 | 0.3678 | 0.562 | 0.550 | 0.375 | 0.368 | 0.337 | 5/16 0.312 | 0.182 | 0.143 | 0.008 |
| 7/16 | 0.4375 | 0.4375 | 0.4294 | 0.656 | 0.642 | 0.438 | 0.430 | 0.394 | 3/8 0.375 | 0.213 | 0.166 | 0.010 |
| 1/2 | 0.5000 | 0.5000 | 0.4919 | 0.750 | 0.735 | 0.500 | 0.492 | 0.450 | 3/8 0.375 | 0.245 | 0.190 | 0.010 |
| 5/8 | 0.6250 | 0.6250 | 0.6163 | 0.938 | 0.921 | 0.625 | 0.616 | 0.562 | 1/2 0.500 | 0.307 | 0.238 | 0.010 |
| 3/4 | 0.7500 | 0.7500 | 0.7406 | 1.125 | 1.107 | 0.750 | 0.740 | 0.675 | 5/8 0.625 | 0.370 | 0.285 | 0.010 |
| 7/8 | 0.8750 | 0.8750 | 0.8647 | 1.312 | 1.293 | 0.875 | 0.864 | 0.787 | 3/4 0.750 | 0.432 | 0.333 | 0.015 |
| 1 | 1.0000 | 1.0000 | 0.9886 | 1.500 | 1.479 | 1.000 | 0.988 | 0.900 | 3/4 0.750 | 0.495 | 0.380 | 0.015 |
| See Notes | 1 | 2,15 | 3 | 4 | 21 | 6 |
“Contact Jade Special Metals today with your requirement for ASTM A193 B7 Bolts. We assure you of the best quote.
ASTM A193 Grade B7 Torque Chart
The following torque values apply to A193 B7 bolts with A194 2H nuts, lubricated with a standard bolt lubricant (K = 0.15). Values are in ft-lbs (Nm in parentheses). Always verify torque requirements with your engineering specification — actual torque values depend on lubrication, surface condition, and joint requirements.
| Bolt Size (in) | TPI | Torque — Dry (ft-lbs) | Torque — Lubricated (ft-lbs) | Torque — Lubricated (Nm) |
|---|---|---|---|---|
| 1/4″ | 20 | 9 | 7 | 9 |
| 5/16″ | 18 | 18 | 14 | 19 |
| 3/8″ | 16 | 32 | 24 | 33 |
| 1/2″ | 13 | 77 | 58 | 79 |
| 5/8″ | 11 | 151 | 113 | 153 |
| 3/4″ | 10 | 267 | 200 | 271 |
| 7/8″ | 9 | 432 | 324 | 439 |
| 1″ | 8 | 648 | 486 | 659 |
| 1-1/8″ | 8 | 916 | 687 | 932 |
| 1-1/4″ | 8 | 1,293 | 970 | 1,315 |
| 1-3/8″ | 8 | 1,748 | 1,311 | 1,778 |
| 1-1/2″ | 8 | 2,299 | 1,725 | 2,339 |
| 1-3/4″ | 8 | 3,778 | 2,834 | 3,843 |
| 2″ | 8 | 5,750 | 4,313 | 5,849 |
| 2-1/4″ | 8 | 8,238 | 6,179 | 8,381 |
| 2-1/2″ | 8 | 11,340 | 8,505 | 11,534 |
⚠️ These are reference torque values. Always consult your project engineer or applicable code (ASME PCC-1, ASME VIII) for final torque requirements.
| A193 Grade B7 Bolts Size | TPI | Proof Load (lbs) | Clamp Load (lbs) | Tightening Torque (ft lbs) Galv + Wax |
Tightening Torque (ft lbs) Galv |
Tightening Torque (ft lbs) Plain |
|---|---|---|---|---|---|---|
| 1/4″ | 20 | 3,350 | 2,513 | 5 | 13 | 10 |
| 9/16″ | 12 | 19,100 | 14,325 | 67 | 168 | 134 |
| 3/8″ | 16 | 8,150 | 6,113 | 19 | 48 | 38 |
| 7/16″ | 14 | 11,150 | 8,363 | 30 | 76 | 61 |
| 5/16″ | 18 | 5,500 | 4,125 | 11 | 27 | 21 |
| 1/2″ | 13 | 14,900 | 11,175 | 47 | 116 | 93 |
| 5/8″ | 11 | 23,750 | 17,813 | 93 | 232 | 186 |
| 1″ | 8 | 63,650 | 47,738 | 398 | 995 | 796 |
| 3/4″ | 10 | 35,050 | 26,288 | 164 | 411 | 329 |
| 7/8″ | 9 | 48,500 | 36,375 | 265 | 663 | 530 |
ASTM A193 Gr B7 Stud Bolt Weight
| Length | 1/2 | 3/4 | 1 | 1-1/4 | 1-1/2 |
|---|---|---|---|---|---|
| 3″ | 0.13 | 0.3 | 0.55 | 0.9 | 1.33 |
| 3-1/4″ | 0.14 | 0.33 | 0.6 | 0.97 | 1.44 |
| 3-1/2″ | 0.15 | 0.35 | 0.65 | 1.05 | 1.55 |
| 4″ | 0.17 | 0.4 | 0.74 | 1.2 | 1.77 |
| 4-1/4″ | 0.18 | 0.43 | 0.79 | 1.27 | 1.88 |
| 4-1/2″ | 0.19 | 0.45 | 0.83 | 1.35 | 1.99 |
| 5″ | 0.22 | 0.51 | 0.93 | 1.5 | 2.22 |
| 5-1/4″ | 0.23 | 0.53 | 0.97 | 1.58 | 2.33 |
| 5-1/2″ | 0.24 | 0.56 | 1.02 | 1.65 | 2.44 |
| 6″ | 0.26 | 0.61 | 1.11 | 1.8 | 2.66 |
| 6-1/4″ | 0.27 | 0.63 | 1.16 | 1.88 | 2.77 |
| 6-1/2″ | 0.28 | 0.66 | 1.2 | 1.95 | 2.88 |
| 7″ | 0.3 | 0.71 | 1.3 | 2.1 | 3.1 |
| 7-1/4″ | 0.31 | 0.73 | 1.34 | 2.18 | 3.21 |
| 7-1/2″ | 0.33 | 0.76 | 1.39 | 2.25 | 3.33 |
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
- Oil & Gas
- Petrochemical & Refining
- Power Generation
- Heavy Construction & Engineering
- Manufacturing
Related Products
FAQ’s About ASTM A193 B7 Bolts
What material is ASTM A193 Grade B7 made from?
ASTM A193 Grade B7 bolts are manufactured from chromium-molybdenum alloy steel, typically AISI grades 4140, 4142, or 4145. The material is quenched and tempered at a minimum temperature of 1150°F (620°C) to achieve the required mechanical properties.
What is the tensile strength of A193 B7 bolts?
For diameters up to 2½ inches, A193 B7 bolts have a minimum tensile strength of 125 ksi (860 MPa) and a minimum yield strength of 105 ksi (725 MPa). Strength values decrease slightly for larger diameter bolts.
What is the difference between A193 B7 and B7M?
Both grades use the same Cr-Mo alloy steel, but B7M is a controlled-hardness version (max. 22 HRC / 235 HBW) that qualifies for sour service per NACE MR0175 / ISO 15156. B7 has higher strength (125 ksi vs. 100 ksi) but no sour-service certification without hardness control.
What nuts are used with ASTM A193 B7 bolts?
ASTM A194 Grade 2H heavy hex nuts are the standard pairing for A193 B7 bolts in high-pressure, high-temperature service. For sour service (NACE MR0175), Grade 2HM heavy hex nuts are specified instead.
What temperature range can A193 B7 bolts handle?
ASTM A193 B7 bolts are rated for service from –50°F (–45°C) up to approximately 900°F (482°C), making them suitable for the vast majority of pressure vessel and industrial piping applications.
Are A193 B7 bolts available in metric sizes?
Yes. A193 B7 fasteners are available in both imperial (inch) and metric sizes. Metric thread configurations comply with ASME B1.13M 6h metric coarse thread standards. Jade Special Metals supplies both series from stock.
What coatings are available for A193 B7 bolts?
Common coating options include plain/black finish (most common), zinc plating, hot-dip galvanizing (note: may affect dimensional tolerances), PTFE/Xylan coating for low-friction assembly, and Molykote/wax lubricant for controlled torque. Please specify your coating requirement when requesting a quote.
Do B7 bolts rust?
Yes. Since A193 B7 is an alloy steel and not a stainless steel, it will rust if exposed to moisture or corrosive environments. To prevent this, B7 bolts are often supplied with a protective coating, such as PTFE (Teflon/Xylan), Zinc Plating, or Hot-Dip Galvanizing, especially when used in outdoor, marine, or chemical plant applications.
