ASTM A193 Alloy Steel Fasteners are high-strength bolting products designed for pressure vessels, valves, flanges, piping systems and other applications exposed to high-temperature and high-pressure service. These fasteners are manufactured from alloy steel grades and are commonly supplied as stud bolts, heavy hex bolts, hex nuts and related bolting components.
We manufacture and supply A193 Alloy Steel Fasteners in grades such as B7, B7M and B16, with options for different dimensions, thread configurations, finishes and testing requirements. Our products are suitable for demanding applications in oil & gas, petrochemical, power generation, chemical processing and industrial equipment.
Common grades: ASTM A193 Grade B7, B7M, B16 and other applicable grades
Product forms: Stud bolts, heavy hex bolts, hex bolts, nuts and threaded
fasteners
Finishes: Plain, black oxide, zinc plated and Hot Dip Galvanized (HDG), where
applicable
What Are ASTM A193 Alloy Steel Fasteners?
ASTM A193 Alloy Steel Fasteners are high-strength alloy steel bolting products used primarily for high-temperature and high-pressure applications. They are specified under ASTM A193/A193M and are commonly used for fastening flanges, valves, pressure vessels, piping systems and industrial equipment.
Grades such as B7, B7M and B16 provide different combinations of strength, hardness and service characteristics. Selection depends on operating temperature, pressure, corrosion or sour-service requirements, dimensional requirements and applicable project specifications.
Table of Contents
- ➤ What Are ASTM A193 Alloy Steel Fasteners?
- ➤ ASTM A193 Alloy Steel Fasteners Grades
- ➤ ASTM A193 High Pressure Bolting Applications
- ➤ ASTM A193 Alloy Steel Fasteners Specifications
- ➤ Chemical Composition of ASTM A193 Alloy Steel Fasteners
- ➤ Mechanical Properties of ASTM A193 Fasteners
- ➤ ASTM A193 Alloy Steel Fasteners Weight Chart
- ➤ ASTM A193 Alloy Steel Fasteners Equivalent Grades
- ➤ Hot Dip Galvanized ASTM A193 Alloy Steel Bolts
- ➤ ASTM A193 Alloy Steel Fasteners Manufacturing Process
- ➤ Why Choose Our ASTM A193 Alloy Steel Fasteners?
- ➤ ASTM A193 Alloy Steel Fasteners Manufacturer in Mumbai
ASTM A193 Alloy Steel Fasteners Grades
The grade is one of the most important factors when selecting A193 fasteners because it determines the material chemistry, heat treatment, mechanical properties and suitability for a particular service environment.
➤ ASTM A193 Grade B7 Fasteners
A193 Gr B7 Stud Bolts are among the most widely used A193 fasteners. Grade B7 is a chromium-molybdenum alloy steel grade generally manufactured from quenched and tempered alloy steel.
We supply AISI 4140 A193 B7 Fasteners for applications requiring high tensile strength and dependable performance under elevated temperature and pressure conditions. They are frequently used with industrial flanges, valves, pressure vessels and piping assemblies.
➤ ASTM A193 Grade B7M Fasteners
A193 B7M Sour Gas Bolting is intended for applications where controlled hardness is important, particularly in sour-service environments.
Low Hardness A193 B7M Fasteners are manufactured with lower hardness requirements than standard B7 fasteners. This makes B7M particularly relevant where project specifications require controlled hardness for resistance to sulfide stress cracking in hydrogen sulfide-containing environments.
For sour-service applications, material selection and testing should always follow the applicable project requirements and standards such as NACE MR0175/ISO 15156, when specified.
➤ ASTM A193 Grade B16 Fasteners
Grade B16 is a chromium-molybdenum-vanadium alloy steel grade designed for high-temperature applications. ASTM A193 Grade B7 / B16 Heavy Hex Bolts and studs are commonly selected for demanding industrial equipment and high-temperature pressure applications.
ASTM A193 High Pressure Bolting Applications
ASTM A193 High Pressure Bolting is used where conventional carbon steel fasteners may not provide the required strength or temperature capability.
Typical applications include:
- Oil and gas pipelines and processing equipment
- Refineries and petrochemical plants
- Pressure vessels and reactors
- Power generation equipment
- Steam and high-temperature piping
- Valves and flanged connections
- Chemical processing equipment
- Heat exchangers
- Industrial boilers
- Offshore and onshore process equipment
The fastener grade should be selected according to pressure, temperature, environmental exposure, equipment design and applicable engineering specifications.
ASTM A193 Alloy Steel Fasteners Specifications
We supply A193 alloy steel fasteners according to customer drawings, applicable ASTM requirements and project specifications.
| Property | Details |
|---|---|
| Standard | ASTM A193 / A193M |
| Material | Alloy Steel |
| Common Grades | B7, B7M, B16 |
| Product Type | Stud Bolts, Heavy Hex Bolts, Hex Bolts, Nuts |
| Manufacturing | Forged / machined as applicable |
| Heat Treatment | Quenched & tempered, according to grade requirements |
| Threads | UNC, UNF and other specified threads |
| Finish | Plain, black oxide, zinc plated, HDG where applicable |
| Sizes | As per standard, drawing or customer requirement |
| Testing | Mechanical, hardness, chemical and other tests as specified |
Chemical Composition of ASTM A193 Alloy Steel Fasteners
| Element | A193 B7 | A193 B7M | A193 B16 |
|---|---|---|---|
| Carbon (C) | 0.37–0.49% | 0.28–0.48%* | 0.36–0.44% |
| Manganese (Mn) | 0.65–1.10% | 0.65–1.10% | 0.45–0.70% |
| Silicon (Si) | 0.15–0.35% | 0.15–0.35% | 0.15–0.35% |
| Phosphorus (P) | 0.035% max | 0.035% max | 0.040% max |
| Sulfur (S) | 0.040% max | 0.040% max | 0.040% max |
| Chromium (Cr) | 0.75–1.20% | 0.75–1.20% | 0.80–1.15% |
| Molybdenum (Mo) | 0.15–0.25% | 0.15–0.25% | 0.44–0.65% |
| Vanadium (V) | — | — | 0.15–0.25% |
Mechanical Properties of ASTM A193 Fasteners
Mechanical requirements for A193 alloy-steel grades depend on grade and fastener diameter. This is especially important for B7, where the minimum tensile and yield strengths change with diameter.
ASTM A193 B7 Mechanical Properties
| Diameter | Tensile Strength, Min. | Yield Strength, Min. | Elongation, Min. | Reduction of Area, Min. | Hardness, Max. |
|---|---|---|---|---|---|
| Up to 2½ in. | 125 ksi / 860 MPa | 105 ksi / 720 MPa | 16% | 50% | 321 HBW / 35 HRC |
| Over 2½ to 4 in. | 115 ksi / 795 MPa | 95 ksi / 655 MPa | 16% | 50% | 321 HBW / 35 HRC |
| Over 4 to 7 in. | 100 ksi / 690 MPa | 75 ksi / 515 MPa | 18% | 50% | 321 HBW / 35 HRC |
ASTM A193 B7M Mechanical Properties
| Diameter | Tensile Strength, Min. | Yield Strength, Min. | Elongation, Min. | Reduction of Area, Min. | Hardness, Max. |
|---|---|---|---|---|---|
| Up to 4 in. | 100 ksi / 690 MPa | 80 ksi / 550 MPa | 18% | 50% | 235 HBW / 99 HRB |
| Over 4 to 7 in. | 100 ksi / 690 MPa | 75 ksi / 515 MPa | 18% | 50% | 235 HBW / 99 HRB |
ASTM A193 B16 Mechanical Properties
| Diameter | Tensile Strength, Min. | Yield Strength, Min. | Elongation, Min. | Reduction of Area, Min. | Hardness, Max. |
|---|---|---|---|---|---|
| Up to 2½ in. | 125 ksi / 860 MPa | 105 ksi / 725 MPa | 18% | 50% | 321 HBW / 35 HRC |
| Over 2½ to 4 in. | 110 ksi / 760 MPa | 95 ksi / 655 MPa | 17% | 45% | 321 HBW / 35 HRC |
| Over 4 to 8 in. | 100 ksi / 690 MPa | 85 ksi / 585 MPa | 16% | 45% | 321 HBW / 35 HRC |
These values are based on the mechanical requirements reported for ASTM A193/A193M ferritic grades.
ASTM A193 Alloy Steel Fasteners Weight Chart
The following is a theoretical weight reference based on solid round bar weight at approximately 7.85 g/cm³. Actual threaded fastener weight will vary because of thread profile, head dimensions, length and machining.
| Nominal Diameter | Approx. Weight kg/m |
|---|---|
| M6 | 0.222 |
| M8 | 0.395 |
| M10 | 0.617 |
| M12 | 0.888 |
| M16 | 1.578 |
| M20 | 2.466 |
| M22 | 2.984 |
| M24 | 3.551 |
| M27 | 4.495 |
| M30 | 5.549 |
| M33 | 6.714 |
| M36 | 7.990 |
| M39 | 9.378 |
| M42 | 10.876 |
| M45 | 12.485 |
| M48 | 14.205 |
| M52 | 16.671 |
| M56 | 19.335 |
| M60 | 22.195 |
ASTM A193 Alloy Steel Fasteners Equivalent Grades
| A193 Grade | Common Material / Equivalent Reference | UNS | Werkstoff No. |
|---|---|---|---|
| B7 | AISI 4140 | G41400 | 1.7225 |
| B7M | AISI 4140 / controlled-hardness variant | G41400 | 1.7225 |
| B16 | Cr-Mo-V Alloy Steel | K14072* | 1.7711 |
Hot Dip Galvanized ASTM A193 Alloy Steel Bolts
Hot Dip Galvanized (HDG) ASTM A193 Alloy Steel Bolts can be supplied for applications where additional protection against atmospheric corrosion is required and the coating is permitted by the applicable specification and purchaser requirements.
HDG involves applying a zinc coating to the steel surface to provide sacrificial corrosion protection. However, galvanizing requirements should be reviewed carefully for high-strength alloy steel fasteners because coating processes can affect dimensional characteristics and require appropriate process controls.
We can supply fasteners with the required surface finish based on the application, drawing and purchasing specification.
ASTM A193 Alloy Steel Fasteners Manufacturing Process
Why Choose Our ASTM A193 Alloy Steel Fasteners?
We understand that industrial fasteners are critical components of pressure-containing assemblies. Therefore, we focus on material traceability, dimensional accuracy and conformity with specified requirements.
Our capabilities include:
- ASTM A193 alloy steel fasteners in multiple grades
- B7, B7M and B16 fasteners
- Custom dimensions and thread configurations
- High-pressure and high-temperature bolting
- HDG and other finishes as applicable
- Inspection and documentation according to requirements
- Export-oriented packing and dispatch
- Support for bulk and project requirements
As an ASTM A193 Alloy Steel Fasteners Manufacturer, we can support customers with product selection, technical documentation and customized requirements.
ASTM A193 Alloy Steel Fasteners Manufacturer in Mumbai
We supply ASTM A193 Alloy Steel Fasteners from Mumbai, India, supporting industrial buyers, distributors, EPC contractors and engineering companies.
Our product range can be supplied for domestic projects as well as international requirements. As an ASTM A193 Alloy Steel Fasteners Exporter in India, we focus on appropriate packaging, documentation and shipment preparation for overseas orders.
For project-specific requirements, customers can provide the grade, size, quantity, thread specification, finish and applicable standard so that we can offer the appropriate fastener configuration.
How to Select the Right ASTM A193 Fastener?
Choosing an A193 fastener should not be based only on bolt size. Consider:
- Grade: B7, B7M, B16 or another specified grade.
- Temperature: Confirm the fastener is appropriate for the operating temperature.
- Pressure: Check the complete bolting assembly against design requirements.
- Service environment: Sour gas and corrosive environments may require additional requirements.
- Hardness: Particularly important for B7M and sour-service applications.
- Dimensions and threads: Verify diameter, length, thread form and tolerances.
- Surface finish: Select plain, coated or galvanized finishes according to application requirements.
- Testing and certification: Confirm MTC, chemical, mechanical, hardness and supplementary testing requirements before ordering.
Order ASTM A193 Alloy Steel Fasteners
Looking for dependable ASTM A193 Alloy Steel Fasteners for high-pressure piping, valves, flanges or industrial equipment?
We supply A193 Alloy Steel Fasteners, including A193 Gr B7 Stud Bolts, B7M sour-service bolting and B16 high-temperature fasteners, in standard and customized configurations.
Share your grade, diameter, length, quantity, thread specification, finish and delivery requirement with us to receive a suitable quotation.
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