Understanding ASTM A193 B16 Stud Bolts: Specifications & Properties
ASTM A193 Grade B16 stud bolts are engineered for high-temperature, high-pressure service in petrochemical, refining, power generation, and industrial processing environments. With exceptional strength and elevated-temperature resistance, B16 fasteners are the go-to choice for bolting applications involving superheated steam, high-temperature hydrocarbons, and thermal cycling.
This page serves as a complete resource for material chemistry, mechanical properties, temperature ratings, compatible nut grades, and common applications of B16 stud bolts.
Key Features of B16 Stud Bolts
High Temperature Rating
ASTM A193 B16 is rated for service temperatures up to 1100°F (593°C), making it ideal for:
Steam lines
High-temperature flanges
Pressure vessels
Heat exchangers
- Furnace and boiler assemblies
Superior Strength
Quenched and tempered microstructure provides:
Minimum tensile strength: 125 ksi
Minimum yield strength: 105 ksi
High hardness without brittleness
Strong resistance to relaxation at elevated temps
Optimized Chemistry for High Stress
B16 alloy chemistry includes:
Chromium – oxidation resistance
Molybdenum – high-temperature strength
Vanadium – grain refinement and creep resistance
This combination ensures long-term reliability under cyclic loading and extreme heat.
Nut Combatibility: Grade 7 & Grade 7L Replacing Grade 4
When mating B16 stud bolts with heavy hex nuts, ASTM standards require compatible strength and temperature resistance.
Important Update:
Grade 4 nuts are being phased out in the industry and are no longer widely supplied.
Current Recommended Nut Grade for B16:
ASTM A194 Grade 7 and Grade 7L Heavy Hex Nuts
Grade 7 nuts offer:
Higher strength than Grade 4
Better performance under thermal cycling
Reliable service in high-temperature bolting applications
Quenched and tempered alloy steel for elevated temperature use
Grade 7 nuts are now the accepted and preferred companion for A193 Grade B16 stud bolts across refineries and power plants.
Manufacturing & Heat Treatment
B16 stud bolts must be:
Quenched and tempered
Tested for hardness, tensile properties, and microstructure
Manufactured from alloy steel that meets exact chemistry ranges
Heat treatment is critical to achieving high-temperature strength and creep resistance.
Mechanical Properties
| Alloy Steel, Quenched & Tempered | Per ASTM A193/A193M-16 | |||||
| Diameter | Tempering Temperature | Tensile Strength | Yield Strength, 0.2% offset | Elongation in 4D | Reduction of Area | Hardness |
| Min | ksi | Min ksi | Min % | Min % | Max | |
| 2 1/2" and under | 1200F | 125 | 105 | 18 | 50 | 321 HBW or 35 HRC |
| over 2 1/2 to 4" | 1200F | 110 | 95 | 17 | 45 | 321 HBW or 35 HRC |
| over 4 to 8" | 1200F | 100 | 85 | 16 | 45 | 321 HBW or 35 HRC |
Chemical Properties
| Per ASTM A193/A193M-16 | ||||||||||
| Grade | Material | Carbon | Manganese | Phosphorus | Sulfur | Silicon | Chromium | Molybdenum | Vanadium | Aluminum |
| % by weight | % by weight | % by weight | % by weight | % by weight | % by weight | % by weight | % by weight | % by weight | ||
| B16 | Chromium- Molybdenum- Vanadium | 0.36-0.47 | 0.45-0.70 | 0.035 max | 0.040 max | 0.15-0.35 | 0.80-1.15 | 0.50-0.65 | 0.25-0.35 | 0.015 max (1) |
- 1. Total of soluble and insoluble.
Your Trusted Source for B16 Stud Bolts
STS Industrial supplies a full range of ASTM A193 Grade B16 Stud Bolts, engineered for high-temperature, high-pressure, and high-stress applications. Manufactured from quenched and tempered alloy steel with full material traceability, these stud bolts deliver exceptional strength, reliability, and performance in critical bolted joints. Available in a wide variety of sizes, lengths, and configurations, they meet the demanding requirements of industries such as oil and gas, petrochemical, power generation, and industrial processing. Our technical team is available to assist with product selection to ensure proper specification, nut compatibility—including A194 Grade 7—and full compliance for your application.