What is ASTM A193 Grade B16?
ASTM A193 Grade B16 is a material specification for alloy steel bolting material covering bolts, stud bolts, hex bolts, threaded rods, screws, and bar stock intended for high-temperature, high-pressure, and special-purpose applications. Grade B16 is manufactured from chromium-molybdenum-vanadium (Cr-Mo-V) alloy steel, quenched and tempered to deliver 860 MPa minimum tensile strength and exceptional strength retention at sustained elevated temperatures.
The material is rated for service from −30°C to 593°C (−20°F to 1,100°F) — the widest temperature range among common ASTM A193 alloy steel grades. The ASME SA193 Grade B16 designation is the technically identical equivalent under the ASME Boiler & Pressure Vessel Code.
Both B7 and B16 are Cr-Mo alloy steels under ASTM A193, but they are not interchangeable above 370°C. B16 contains vanadium (0.25–0.35%) and a higher molybdenum content (0.50–0.65% vs 0.15–0.25% in B7). Vanadium forms stable carbides that pin grain boundaries at temperature, preventing the creep and stress relaxation that causes B7 bolts to lose clamping load in sustained high-temperature service.
| Alloy | Cr-Mo (no V) |
| Tensile (≤M64) | 860 MPa |
| Max temp. | 370°C (700°F) |
| Vanadium | No |
| Nut match | A194 Gr. 2H |
| Molybdenum (Mo) | 0.15–0.25% |
| Thermal Expansion | ~12.3 × 10⁻⁶ mm/mm/°C |
| Alloy | Cr-Mo-V |
| Tensile (≤M64) | 860 MPa |
| Max temp. | 593°C (1100°F) |
| Vanadium | Yes |
| Nut match | A194 Gr. 16 |
| Molybdenum (Mo) | 0.50–0.65% |
| Thermal Expansion | ~7.5 × 10⁻⁶ in/in/°F (13.5 × 10⁻⁶ mm/mm/°C) |
Chemical Composition of ASTM A193 B16 Bolts
ASTM A193 B16 is a chromium-molybdenum-vanadium (Cr-Mo-V) alloy steel. The vanadium addition absent in Grade B7 is responsible for its superior high-temperature strength.
| Element | C | Mn | P (max) | S (max) | Si | Cr | Mo | V | Al (max) |
|---|---|---|---|---|---|---|---|---|---|
| Range (%) | 0.36–0.47 | 0.45–0.70 | 0.035 | 0.040 | 0.15–0.35 | 0.80–1.15 | 0.50–0.65 | 0.25–0.35 | 0.015 |
| Product Var. (±) | 0.02 | 0.03 | 0.005 | 0.005 | 0.02 | 0.05 | 0.03 | 0.03 | — |
Mechanical Properties of ASTM A193 Grade B16 Bolts
Mechanical requirements vary by bolt diameter. Values per ASTM A193 / ASME SA193 Grade B16.
Metric (SI)
| Diameter | Min. Tempering Temp. (°C) | Tensile Min (MPa) | Yield Min 0.2% (MPa) | Elong. Min (%) | Red. Area Min (%) | Hardness Max |
|---|---|---|---|---|---|---|
| M64 and under | 650°C | 860 | 725 | 18 | 50 | 321 HBW / 35 HRC |
| Over M64 to M100 | 650°C | 760 | 655 | 17 | 45 | 321 HBW / 35 HRC |
| Over M100 to M180 | 650°C | 690 | 585 | 16 | 45 | 321 HBW / 35 HRC |
Imperial (US Customary)
| Diameter | Min. Tempering Temp. (°F) | Tensile Min (ksi) | Yield Min 0.2% (ksi) | Elong. Min (%) | Red. Area Min (%) | Hardness Max |
|---|---|---|---|---|---|---|
| 2½” and under | 1200°F | 125 | 105 | 18 | 50 | 321 HBW / 35 HRC |
| Over 2½” to 4″ | 1200°F | 110 | 95 | 17 | 45 | 321 HBW / 35 HRC |
| Over 4″ to 7″ | 1200°F | 100 | 85 | 16 | 45 | 321 HBW / 35 HRC |
Specification & Dimensions
| Parameter | Details |
|---|---|
| Standard | ASTM A193 / ASME SA193 Grade B16 |
| Dimensions | ASME B18.2.1 (inch), ASME B18.2.3.3M (metric hex), ASME B18.3 (socket cap) |
| Thread | ASME B1.1 2A/3A — Unified Inch; ASME B1.13M 6h — Metric Coarse |
| Size Range | ¾” to 8″ (inch) / M12 to M200 (metric) |
| Length Range | Custom lengths; standard 1″ to 36″ |
| Heat Treatment | Quenched & Tempered — min. 860°C (1575°F); tempering min. 650°C (1200°F) |
| Hardness | 321 HBW max / 35 HRC max |
| Dual Certification | Dual certified per ASTM & ASME codes |
| NACE Compliance | NACE MR0103 / MR0175 / ISO 15156 |
| PED | PED 2014/68/EU; Merkblatt AD 2000 W2 |
| Marking | Manufacturer’s ID mark + “B16” |
| Finish | Plain, Hot-Dip Galvanized, Black Oxide, Xylan, PTFE |
| UNS No. | K14072 |
For matching nuts, ASTM A194 Grade 7 Nuts and Grade 4 Nuts are the recommended pairing for B16 bolts
Available Product Types
ASTM A193 Grades
Explore all grades available under the ASTM A193 bolting material specification from Jade Alloys.
Dimension Chart – ASTM A193 B16 Stud Bolts & Hex Bolts
Standard dimensions per ASME B18.2.1 (inch) and ASME B18.2.3.3M (metric). Custom lengths available on request.
Inch Series
| Nom. Dia (in) | Thread | Threads/in | W.A.F. (in) | Hvy Hex Hd (in) | Min L (in) | Max L (in) | Wt/pc (kg) |
|---|---|---|---|---|---|---|---|
| 3/4″ | 3/4–10 UNC | 10 | 1-1/4 | 41/64 | 2 | 36 | 0.15 |
| 7/8″ | 7/8–9 UNC | 9 | 1-7/16 | 49/64 | 2 | 36 | 0.21 |
| 1″ | 1–8 UNC | 8 | 1-5/8 | 55/64 | 2.5 | 36 | 0.30 |
| 1-1/8″ | 1-1/8–7 UNC | 7 | 1-13/16 | 63/64 | 2.5 | 36 | 0.42 |
| 1-1/4″ | 1-1/4–7 UNC | 7 | 2 | 1-3/64 | 3 | 36 | 0.54 |
| 1-3/8″ | 1-3/8–6 UNC | 6 | 2-3/16 | 1-11/64 | 3 | 36 | 0.70 |
| 1-1/2″ | 1-1/2–6 UNC | 6 | 2-3/8 | 1-19/64 | 3.5 | 36 | 0.88 |
| 1-3/4″ | 1-3/4–5 UNC | 5 | 2-3/4 | 1-35/64 | 4 | 36 | 1.25 |
| 2″ | 2–4.5 UNC | 4.5 | 3-1/8 | 1-51/64 | 4 | 36 | 1.75 |
| 2-1/2″ | 2-1/2–4 UNC | 4 | 3-7/8 | 2-13/64 | 5 | 36 | 2.90 |
| 3″ | 3–4 UNC | 4 | 4-5/8 | 2-39/64 | 6 | 36 | 4.50 |
| 3-1/2″ | 3-1/2–4 UNC | 4 | 5-3/8 | 3-5/64 | 7 | 36 | 6.30 |
| 4″ | 4–4 UNC | 4 | 6-1/8 | 3-35/64 | 8 | 36 | 8.60 |
Metric Series
| Nom. Dia (mm) | Thread Pitch (mm) | W.A.F. (mm) | Hvy Hex Hd (mm) | Min L (mm) | Max L (mm) | Wt/pc (kg) |
|---|---|---|---|---|---|---|
| M16 | 2.0 | 27 | 14 | 50 | 900 | 0.15 |
| M20 | 2.5 | 34 | 18 | 60 | 900 | 0.25 |
| M24 | 3.0 | 41 | 22 | 70 | 900 | 0.38 |
| M30 | 3.5 | 50 | 26 | 90 | 900 | 0.65 |
| M36 | 4.0 | 60 | 31 | 110 | 900 | 1.05 |
| M42 | 4.5 | 70 | 34 | 130 | 900 | 1.55 |
| M48 | 5.0 | 80 | 38 | 150 | 900 | 2.20 |
| M56 | 5.5 | 90 | 45 | 170 | 900 | 3.20 |
| M64 | 6.0 | 100 | 51 | 190 | 900 | 4.30 |
| M72 | 6.0 | 115 | 58 | 220 | 900 | 5.60 |
| M80 | 6.0 | 125 | 64 | 240 | 900 | 7.20 |
| M100 | 6.0 | 155 | 80 | 300 | 900 | 12.50 |
Note: Dimensions indicative per ASME B18.2.1 / B18.2.3.3M. Custom sizes supplied per drawing.
Need a specific diameter or custom length? Send us your bolt schedule and we'll confirm availability and lead time within 24 hours.
Request a Quote Download DatasheetRecommended Mating Hardware
| Component | Specification | Notes |
|---|---|---|
| Nuts | ASTM A194 Grade 16 | Heavy hex; recommended for all B16 stud bolts |
| Washers | ASTM F436 Type 1 | Hardened; for structural and pressure applications |
| Alt. Nuts (hot service) | ASTM A194 Grade 4, Grade 7 | Where Grade 16 is not available or specified |
ASTM A193 B16 Bolt Torque Chart
Recommended Tightening Torque – ft-lbs (100% Final Torque)
The following torque values are for lubricated fasteners with A194 Grade 4 nuts. Apply torque in three stages: 30% initial, 70% intermediate, 100% final. Always verify with a torque wrench calibrated per ISO 6789.
| Bolt Diameter | 30% Initial Torque (ft-lbs) | 70% Torque (ft-lbs) | 100% Final Torque (ft-lbs) | 100% Final Torque (Nm) |
|---|---|---|---|---|
| 1/2″ | 17 | 39 | 55 | 75 |
| 9/16″ | 24 | 55 | 80 | 108 |
| 5/8″ | 33 | 77 | 110 | 149 |
| 3/4″ | 59 | 137 | 195 | 264 |
| 7/8″ | 93 | 217 | 310 | 420 |
| 1″ | 140 | 325 | 465 | 630 |
| 1-1/8″ | 205 | 480 | 685 | 929 |
| 1-1/4″ | 288 | 672 | 960 | 1302 |
| 1-3/8″ | 391 | 915 | 1305 | 1769 |
| 1-1/2″ | 518 | 1208 | 1725 | 2339 |
| 1-3/4″ | 840 | 1960 | 2800 | 3796 |
| 2″ | 1280 | 2985 | 4265 | 5783 |
| 2-1/4″ | 1850 | 4315 | 6165 | 8359 |
| 2-1/2″ | 2565 | 5985 | 8550 | 11592 |
| 2-3/4″ | 3121 | 7282 | 10400 | 14101 |
| 3″ | 4080 | 9520 | 13600 | 18439 |
Note: Torque values assume K = 0.20 (standard lubricated condition). Adjust K factor for dry (K=0.20), lightly oiled (K=0.15), or PTFE/anti-seize coated (K=0.12) conditions. Always consult the engineering specification for project-specific torque values.
ASTM A193 B16 Heavy Hex Bolts – Dimension Chart (Metric)
| Grade & Class | Diameter Range | Tensile Strength Min. | Yield Strength Min. | Elongation Min. | Reduction of Area Min. | Hardness Max (Brinell) | Hardness Max (Rockwell) |
|---|---|---|---|---|---|---|---|
| B16 Studs | Up to 2-1/2″ | 125 ksi | 105 ksi | 18% | 50% | 321 HBW | C35 |
| B16 Studs | Over 2-1/2″ to 4″ | 110 ksi | 95 ksi | 17% | 45% | 321 HBW | C35 |
| B16 Studs | Over 4″ to 7″ | 100 ksi | 85 ksi | 16% | 45% | 321 HBW | C35 |
ASTM A193 B16 Bolt Weight Chart (Approximate)
Approximate weights per piece for standard A193 B16 Hex Bolts in alloy steel. Actual weight varies by length, thread type, and head configuration. Contact Jade Alloys for precise weight calculations for your order.
| Nominal Diameter | Thread (TPI) | Length (inches) | Approx. Weight per piece (kg) | Pieces per 50 kg |
|---|---|---|---|---|
| 1/2″ (M12) | 13 | 2″ | 0.045 | ~1111 |
| 5/8″ (M16) | 11 | 2-1/2″ | 0.090 | ~556 |
| 3/4″ (M20) | 10 | 3″ | 0.160 | ~312 |
| 7/8″ (M22) | 9 | 3-1/2″ | 0.240 | ~208 |
| 1″ (M24) | 8 | 4″ | 0.380 | ~131 |
| 1-1/4″ (M30) | 7 | 5″ | 0.720 | ~69 |
| 1-1/2″ (M36) | 6 | 6″ | 1.250 | ~40 |
| 1-3/4″ (M42) | 5 | 7″ | 2.000 | ~25 |
| 2″ (M48) | 4.5 | 8″ | 3.100 | ~16 |
| 2-1/2″ (M64) | 4 | 10″ | 6.000 | ~8 |
| 3″ (M72) | 4 | 12″ | 10.500 | ~4.7 |
Use our online Bolts Weight Chart Calculator on jadealloys.com for exact weight calculations based on your specific bolt dimensions and quantities.
International Grade Equivalents
Industries & Applications
Grade B16 bolts are the preferred choice wherever sustained high-temperature bolting is required under pressure.
Frequently Asked Questions
What is ASTM A193 Grade B16?
ASTM A193 Grade B16 is a material specification for alloy steel bolting material manufactured from chromium-molybdenum-vanadium (Cr-Mo-V) steel. The material is quenched and tempered to achieve high tensile strength and excellent high-temperature performance, making it suitable for service from -30°C to 593°C (-20°F to 1100°F).
What is the maximum service temperature for B16 bolts?
ASTM A193 B16 bolts are rated for service from -30°C (-20°F) up to 593°C (1100°F). The vanadium content in B16 is specifically responsible for retaining strength at temperatures above 370°C, where Grade B7 begins to lose performance.
What is the difference between A193 B16 and B7?
Both Grade B7 and Grade B16 are Cr-Mo alloy steels under ASTM A193. B16 adds vanadium (0.25–0.35%) to the composition, which significantly improves strength retention at high temperatures. B16 is the recommended grade for continuous service above 370°C (700°F).
What nuts and washers are used with A193 B16 bolts?
The recommended mating hardware is ASTM A194 Grade 16 heavy hex nuts and ASTM F436 Type 1 hardened washers. These pairings are required for ASME pressure vessel and piping code compliance.
Is ASTM A193 B16 the same as ASME SA193 B16?
Yes. ASME SA193 Grade B16 is the ASME Boiler & Pressure Vessel Code edition of ASTM A193 Grade B16. The chemical composition and mechanical requirements are identical.
What heat treatment is required for A193 B16?
ASTM A193 Grade B16 requires quench and temper heat treatment. The quench temperature is a minimum of 860°C (1575°F), followed by tempering at a minimum of 650°C (1200°F).
Does Jade Alloys supply Mill Test Certificates with B16 bolts?
Yes. All ASTM A193 B16 bolts from Jade Alloys come with full Mill Test Certificates (MTCs) conforming to EN 10204 3.1. Third-party inspections (TPIA), NABL lab reports, and PMI testing are available on request.
Is ASTM A193 B16 suitable for sour service (H₂S environments)?
ASTM A193 B16 is listed in NACE MR0103 and MR0175 / ISO 15156 with hardness limits of 321 HBW / 35 HRC max. Where sour service compliance is required, the 35 HRC hardness cap must be confirmed on the MTC. Consult NACE MR0175 Table A.2 for full applicability conditions.
Countries We Export ASTM A193 B16 Bolts To
Jade Alloys exports ASTM A193 B16 Bolts to over 40 countries across all major industrial regions.
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