ASTM A193 B7 Stud Bolts
ASTM A193 Grade B7 stud bolts are high-strength, heat-treated alloy steel fasteners commonly used in high-pressure and high-temperature industrial applications. Manufactured from chromium-molybdenum alloy steel, B7 studs are widely specified for flange connections, pressure vessels, valves, heat exchangers, and industrial piping systems.
RAM Threading manufactures and supplies ASTM A193 B7 stud bolts for customers in the oil and gas, petrochemical, refining, power generation, and industrial manufacturing industries. We offer B7 studs in a variety of sizes, lengths, thread configurations, and finishes, including plain, PTFE-coated, and black oxide options.
Whether you need standard B7 stud bolts, custom lengths, or compatible ASTM A194 Grade 2H heavy hex nuts, RAM Threading can help you source the fasteners required for your application.
Key Features
- High-strength chromium-molybdenum alloy steel (AISI 4140/4142)
- Heat-treated (quenched and tempered) for superior mechanical properties
- Designed for high-pressure and high-temperature service
- Full-length threading for maximum engagement and load distribution
- Excellent tensile strength (up to 125,000 PSI)
- Compatible with ASTM A194 Grade 2H heavy hex nuts
Applications of ASTM A193 B7 Stud Bolts
- Oil & gas refineries
- Petrochemical processing plants
- Pressure vessels and flanges
- Power generation facilities
- Heat exchangers
- Industrial piping systems
ASTM A193 B7 Stud Bolt Sizes & Availability
RAM Threading stocks select ASTM A193 Grade B7 stud bolt sizes for industrial bolting applications, with additional lengths available through our in-house cutting capabilities. We maintain an inventory of B7 threaded rod, allowing us to cut studs to customer-specified lengths for flange connections, piping systems, valves, and other industrial applications.
Common Stocked B7 Stud Bolt Sizes
The following sizes are among the standard B7 stud bolt configurations we keep ready in our warehouse:
| Diameter | Length |
|---|---|
| 1/4″ | 1-4″ |
| 5/16″ | 1-4″ |
| 3/8″ | 1-6″ |
| 1/2″ | 1-7″ |
| 5/8″ | 2-8″ |
| 3/4″ | 2 1/2-10″ |
| 7/8″ | 4-10″ |
| 1″ | 4-10″ |
| 1 1/8″ | 5 1/4-9″ |
| 1 1/4″ | 7-10″ |
| 1 3/8″ | 9-10 1/2″ |
| 1 1/2″ | 10″ |
Custom-Length ASTM A193 B7 Stud Bolts
Need a B7 stud bolt length that isn’t listed above?
RAM Threading maintains B7 threaded rod inventory and offers in-house cutting to accommodate custom stud bolt lengths. Whether you’re sourcing replacement flange bolting or ordering fasteners for a new industrial project, we can help provide studs manufactured to your dimensional requirements.
Submit your required diameter, length, finish, and quantity for a quote.
Commonly Paired With 2H Heavy Hex Nut
ASTM A193 B7 stud bolts are most commonly paired with ASTM A194 Grade 2H heavy hex nuts to create a reliable, high-strength fastening assembly for demanding applications. This combination is specifically designed to handle high-pressure and high-temperature environments, ensuring proper load distribution, secure engagement, and consistent performance in critical bolted connections.
At RAM Threading, we supply both B7 stud bolts and 2H heavy hex nuts to ensure full compatibility, helping customers achieve dependable performance across flanges, pressure vessels, and industrial piping systems.
Per ASTM A193
| 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 | 1100°F | 125 | 105 | 16 | 50 | 321 HBW or 35 HRC |
| Over 2 1/2″ to 4″ | 1100°F | 115 | 95 | 16 | 50 | 321 HBW or 35 HRC |
| Over 4″ to 7″ | 1100°F | 100 | 75 | 18 | 50 | 321 HBW or 35 HRC |
B7 Chemical Properties
Per ASTM A193
| Grade | Material | Carbon | Manganese | Phosphorus | Sulfur | Silicon | Chromium | Molybdenum |
|---|---|---|---|---|---|---|---|---|
| % by weight | % by weight | % by weight | % by weight | % by weight | % by weight | % by weight | ||
| B7 | Alloy Steel | 0.38–0.48 (1) | 0.75–1.00 | 0.035 max | 0.040 max | 0.15–0.35 | 0.80–1.10 | 0.15–0.25 |
| Standard | Description |
|---|---|
| ASTM A193 / A193M | Covers alloy steel bolting materials for high-temperature and high-pressure service, including mechanical and chemical requirements for Grade B7 stud bolts. |
| ASME B18.31.2 | Defines dimensional and general data for continuous thread and double-end stud bolts. |
| ASME B1.1 UNC & UNF Class 2A |
Specifies thread form, series, class, tolerance, and designation for unified screw threads. |
| ASTM A194 Grade 2H |
Specifies carbon and alloy steel nuts commonly used with ASTM A193 Grade B7 stud bolts (when supplied). |
| ASME B16.5 / B16.47 | Provides flange dimensional requirements and bolting guidelines for pressure-rated flanges. |
| Flange Class | Bolting | Nominal Pipe Diameter (inches) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3/4 | 1 | 1-1/4 | 1-1/2 | 2 | 2-1/2 | 3 | 3-1/2 | 4 | ||
| 150# | Number | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 8 | 8 |
| Diameter | 1/2 | 1/2 | 1/2 | 1/2 | 1/2 | 5/8 | 5/8 | 5/8 | 5/8 | 5/8 | |
| Stud Bolt Length | 2-1/4 | 2-1/2 | 2-1/2 | 2-3/4 | 2-3/4 | 3-1/4 | 3-1/2 | 3-1/2 | 3-1/2 | 3-1/2 | |
| Mach Bolt Length | 2 | 2 | 2-1/4 | 2-1/4 | 2-1/2 | 2-3/4 | 3 | 3 | 3 | 3 | |
| 300# | Number | 4 | 4 | 4 | 4 | 4 | 8 | 8 | 8 | 8 | 8 |
| Diameter | 1/2 | 5/8 | 5/8 | 5/8 | 3/4 | 5/8 | 3/4 | 3/4 | 3/4 | 3/4 | |
| Stud Bolt Length | 2-1/2 | 3 | 3 | 3-1/4 | 3-1/2 | 3-1/2 | 4 | 4-1/4 | 4-1/4 | 4-1/2 | |
| Mach Bolt Length | 2-1/4 | 2-1/2 | 2-1/2 | 2-3/4 | 3 | 3 | 3-1/4 | 3-1/2 | 3-3/4 | 3-3/4 | |
| 600# | Number | 4 | 4 | 4 | 4 | 4 | 8 | 8 | 8 | 8 | 8 |
| Diameter | 1/2 | 5/8 | 5/8 | 5/8 | 3/4 | 5/8 | 3/4 | 3/4 | 7/8 | 7/8 | |
| Stud Bolt Length | 3 | 3-1/2 | 3-1/2 | 3-3/4 | 4-1/4 | 4-1/4 | 4-3/4 | 5 | 5-1/2 | 5-3/4 | |
| 900# | Number | 4 | 4 | 4 | 4 | 4 | 8 | 8 | 8 | – | 8 |
| Diameter | 3/4 | 3/4 | 7/8 | 7/8 | 1 | 7/8 | 1 | 7/8 | – | 1-1/8 | |
| Stud Bolt Length | 4-1/4 | 4-1/2 | 5 | 5 | 5-1/2 | 5-3/4 | 6-1/4 | 5-3/4 | – | 6-3/4 | |
| 1500# | Number | 4 | 4 | 4 | 4 | 4 | 8 | 8 | 8 | – | 8 |
| Diameter | 3/4 | 3/4 | 7/8 | 7/8 | 1 | 7/8 | 1 | 1-1/8 | – | 1-1/4 | |
| Stud Bolt Length | 4-1/4 | 4-1/2 | 5 | 5 | 5-1/2 | 5-3/4 | 6-1/4 | 7 | – | 7-3/4 | |
| 2500# | Number | 4 | 4 | 4 | 4 | 4 | 8 | 8 | 8 | – | 8 |
| Diameter | 3/4 | 3/4 | 7/8 | 1 | 1-1/8 | 1 | 1-1/8 | 1-1/4 | – | 1-1/2 | |
| Stud Bolt Length | 4-3/4 | 5 | 5-1/2 | 6 | 6-3/4 | 7 | 7-3/4 | 8-3/4 | – | 10 | |
| Flange Class | Bolting | Nominal Pipe Diameter (inches) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 24 | ||
| 150# | Number | 8 | 8 | 8 | 12 | 12 | 12 | 16 | 16 | 20 | 20 |
| Diameter | 3/4 | 3/4 | 3/4 | 7/8 | 7/8 | 1 | 1 | 1-1/8 | 1-1/8 | 1-1/4 | |
| Stud Bolt Length | 3-3/4 | 4 | 4-1/4 | 4-1/2 | 4-3/4 | 5-1/4 | 5-1/4 | 5-3/4 | 6-1/4 | 6-3/4 | |
| Mach Bolt Length | 3-1/4 | 3-1/4 | 3-1/2 | 4 | 4 | 4-1/2 | 4-1/2 | 5 | 5-1/2 | 6 | |
| 300# | Number | 8 | 12 | 12 | 16 | 16 | 20 | 20 | 24 | 24 | 24 |
| Diameter | 3/4 | 3/4 | 7/8 | 1 | 1-1/8 | 1-1/8 | 1-1/4 | 1-1/4 | 1-1/4 | 1-1/2 | |
| Stud Bolt Length | 4-3/4 | 4-3/4 | 5-1/2 | 6-1/4 | 6-3/4 | 7 | 7-1/2 | 7-3/4 | 8 | 9 | |
| Mach Bolt Length | 4-1/4 | 4-1/4 | 4-3/4 | 5-1/2 | 5-3/4 | 6-1/4 | 6-1/2 | 6-3/4 | 7-1/4 | 8 | |
| 600# | Number | 8 | 12 | 12 | 16 | 20 | 20 | 20 | 20 | 24 | 24 |
| Diameter | 1 | 1 | 1-1/8 | 1-1/4 | 1-1/4 | 1-3/8 | 1-1/2 | 1-5/8 | 1-5/8 | 1-7/8 | |
| Stud Bolt Length | 6-1/2 | 6-3/4 | 7-1/2 | 8-1/2 | 8-3/4 | 9-1/4 | 10 | 10-3/4 | 11-1/4 | 13 | |
| 900# | Number | 8 | 12 | 12 | 16 | 20 | 20 | 20 | 20 | 20 | 20 |
| Diameter | 1-1/4 | 1-1/8 | 1-3/8 | 1-3/8 | 1-3/8 | 1-1/2 | 1-5/8 | 1-7/8 | 2 | 2-1/2 | |
| Stud Bolt Length | 7-1/2 | 7-1/2 | 8-3/4 | 9-1/4 | 10 | 10-3/4 | 11-1/4 | 12-3/4 | 13-3/4 | 17-1/4 | |
| 1500# | Number | 8 | 12 | 12 | 12 | 16 | 16 | 16 | 16 | 16 | 16 |
| Diameter | 1-1/2 | 1-3/8 | 1-5/8 | 1-7/8 | 2 | 2-1/4 | 2-1/2 | 2-3/4 | 3 | 3-1/2 | |
| Stud Bolt Length | 9-3/4 | 10-1/4 | 11-1/2 | 13-1/4 | 14-3/4 | 16 | 17-1/2 | 19-1/2 | 21-1/4 | 24-1/4 | |
| 2500# | Number | 8 | 8 | 12 | 12 | 12 | – | – | – | – | – |
| Diameter | 1-3/4 | 2 | 2 | 2-1/2 | 2-3/4 | – | – | – | – | – | |
| Stud Bolt Length | 11-3/4 | 13-1/2 | 15 | 19-1/4 | 21-1/4 | – | – | – | – | – | |
Coating & Finish Options
ASTM A193 B7 stud bolts are available in a range of coatings to meet different environmental and performance requirements. Selecting the right finish helps improve corrosion resistance, reduce installation issues, and extend service life.
- Plain Finish – standard for general applications
- Black Oxide – light corrosion resistance
- PTFE Coated – ideal for corrosive environments and reduces galling
Plain Finish B7 Stud Bolts
Plain finish ASTM A193 B7 stud bolts are supplied without any additional coating, making them a reliable and cost-effective option for general-purpose industrial applications. Commonly used in controlled or non-corrosive environments, plain B7 studs provide the full strength and performance of heat-treated alloy steel without the added cost of surface treatments.
Because there is no coating layer, plain finish stud bolts maintain precise thread dimensions, allowing for consistent fit and proper engagement with mating components such as ASTM A194 Grade 2H heavy hex nuts. These stud bolts are widely used in oil & gas, petrochemical, and industrial applications where high strength is required and corrosion exposure is minimal.
PTFE Coated B7 Stud Bolts
PTFE-coated B7 stud bolts are designed for corrosive and demanding environments where additional protection and performance are required. The PTFE coating provides excellent resistance to chemicals, moisture, and environmental exposure, making it ideal for use in oil & gas, petrochemical, and marine applications.
In addition to corrosion resistance, PTFE coatings reduce friction during installation, helping to prevent galling and allowing for more consistent torque values. This makes PTFE-coated B7 stud bolts a preferred choice for critical bolted connections where reliability and ease of installation are essential.
Benefits of PTFE Coated B7 Stud Bolts
- Corrosion protection for demanding industrial environments
- Reduced friction during assembly
- Improved resistance to galling and thread seizure
- Coating options for specific application requirements
Common Applications
PTFE coated B7 stud bolts are commonly specified for flange connections, piping systems, petrochemical facilities, refineries, and industrial processing equipment.
Sizes and Availability
RAM Threading offers B7 stud bolts in a range of diameters and lengths, with PTFE coating options available based on project specifications. Contact our team to confirm sizes, coating requirements, and current availability.
Black Oxide B7 Stud Bolts
Black oxide B7 stud bolts feature a conversion coating that provides light corrosion resistance while maintaining the dimensional accuracy of the fastener. This finish is commonly used in indoor or controlled environments where minimal protection is required, and maintaining a clean, uniform appearance is important.
Because black oxide does not add thickness to the stud bolt, it allows for smooth thread engagement and consistent installation without affecting fit. ASTM A193 B7 black oxide stud bolts are a cost-effective solution for applications where strength and precision are critical, but exposure to harsh environmental conditions is limited.
Benefits of Black Oxide B7 Stud Bolts
-
Minimal dimensional change: Black oxide produces a thin conversion layer that helps maintain thread dimensions.
-
Uniform appearance: Creates a consistent black finish across the fastener surface.
-
Mild corrosion resistance: When properly oiled or sealed, black oxide can provide limited protection against surface oxidation.
-
Industrial versatility: Suitable for applications where a black finish is specified and more protective coatings are not required.
Common Applications
Black oxide B7 stud bolts may be specified for industrial machinery, equipment assembly, maintenance applications, and certain piping or bolted connections where the finish meets project requirements.
Sizes and Availability
RAM Threading offers ASTM A193 Grade B7 stud bolts in a variety of diameters and lengths. Black oxide finishing options may be available based on size, quantity, and project specifications.
Contact our team to discuss black oxide B7 stud bolt requirements, available sizes, and current lead times.
Need B7 Threaded Rod or All Thread?
RAM Threading also stocks full 12-foot lengths of ASTM A193 B7 threaded rod and all thread, with custom cut-to-length services available for industrial fastening applications. Contact our team for sizes, availability, and pricing.
FAQS
Request a Quote for ASTM A193 B7 Stud Bolts
Looking for a reliable supplier of ASTM A193 B7 stud bolts? RAM Threading supplies industrial stud bolts, threaded fasteners, and compatible heavy hex nuts for refinery, petrochemical, oil and gas, and industrial applications. Whether you need standard B7 studs, custom lengths, or coated fasteners, our team can assist with product availability, specifications, and pricing.
Contact RAM Threading for a quote on your next B7 stud bolt order.
To help us quote accurately, please include your required diameter, length, finish, quantity, and any applicable material or certification requirements.