Stainless Steel 347 / 347H Bolts Supplier & Exporter
Aurum Overseas is a trusted global manufacturer and supplier of premium quality Stainless Steel 347 Bolts and 347H Bolts manufactured for industrial applications requiring excellent corrosion resistance, superior high temperature strength, and long-term performance in aggressive service environments. These niobium stabilized stainless steel bolting solutions are widely used in refinery systems, petrochemical plants, power generation equipment, heat exchangers, pressure vessels, thermal processing systems, and high temperature industrial assemblies where structural reliability is critical.
The 347 stainless steel family belongs to the austenitic chromium nickel stainless steel category developed specifically for applications exposed to elevated temperatures and repeated welding conditions. Unlike conventional stainless steel grades, the addition of columbium (niobium) stabilizes the alloy and improves resistance against chromium carbide precipitation during high temperature service. SS 347H Bolts contain higher carbon content compared to standard 347 grade, offering improved creep resistance and better mechanical stability in continuous elevated temperature applications.
As an experienced exporter, Aurum Overseas supplies certified stainless steel fastening solutions manufactured according to ASTM, ASME, DIN, ISO, and global industrial standards for demanding engineering projects worldwide.
SS 347 / SS 347H Stainless Steel Bolts – Product Overview
Stainless Steel 347 Bolts are engineered for applications where corrosion resistance and thermal stability must be maintained during prolonged exposure to elevated operating temperatures. The niobium stabilization prevents carbide precipitation after welding, making the material highly suitable for fabricated structures operating in corrosive and high temperature environments.
Stainless Steel 347H Bolts are the higher carbon version of standard 347 stainless steel designed specifically for applications requiring improved creep strength and long-term mechanical performance under continuous thermal exposure. These properties make the alloy highly suitable for pressure vessels, superheaters, heat exchangers, refinery systems, and industrial furnace equipment.
Industries requiring oxidation resistant and thermally stable stainless steel fastening systems often specify 347 series bolts because of their ability to perform reliably under demanding operating conditions.
Specifications of Stainless Steel 347 / 347H Bolts
| Specification | Details |
|---|---|
| Product | Stainless Steel 347 / 347H Bolts |
| Grades | SS 347, SS 347H |
| ASTM Standard | ASTM A193 |
| ASME Standard | ASME SA193 |
| International Standards | DIN, ISO, JIS, GB, IS, BS, ASTM |
| Size | M3 – M100 |
| Bolt Length | 3 mm – 200 mm |
| Bolt / Screw Size | M3 – M56 |
| Nuts Size | M3 – M56 |
| Machine Screw Size | M1.6 – M12 |
| Dimensions | DIN 931, 933, 934, ASME B18.2.1 |
| Manufacturing | Hot Forged, Cold Forged, CNC Machined |
| Certification | EN 10204 3.1 / MTC |
Mechanical Properties of SS 347 & SS 347H Bolts
While both grades provide excellent corrosion resistance and oxidation resistance, SS 347H is designed for better high temperature strength.
| Property | SS 347 | SS 347H |
|---|---|---|
| Tensile Strength | 515 MPa | 530 MPa |
| Yield Strength | 205 MPa | 210 MPa |
| Elongation | 40% | 40% |
| Hardness | 201 HB Max | 201 HB Max |
| Density | 7.96 g/cm³ | 7.96 g/cm³ |
| Temperature Resistance | High | Very High |
| Creep Resistance | Good | Better |
Chemical Composition of SS 347 & SS 347H Stainless Steel Bolts
The addition of niobium improves stabilization and helps resist intergranular corrosion during welding and thermal exposure.
| Element | SS 347 | SS 347H |
|---|---|---|
| Chromium | 17 – 19% | 17 – 19% |
| Nickel | 9 – 13% | 9 – 13% |
| Carbon | 0.08 Max | 0.04 – 0.10 |
| Niobium + Tantalum | 10x Carbon Min | 10x Carbon Min |
| Manganese | 2.0 Max | 2.0 Max |
| Silicon | 1.0 Max | 1.0 Max |
| Sulfur | 0.03 Max | 0.03 Max |
| Phosphorus | 0.045 Max | 0.045 Max |
| Iron | Balance | Balance |
Equivalent Grades of Stainless Steel 347 Series Bolts
| Standard | SS 347 | SS 347H |
|---|---|---|
| UNS | S34700 | S34709 |
| ASTM | 347 | 347H |
| EN | 1.4550 | 1.4961 |
| DIN | X6CrNiNb18-10 | X8CrNiNb16-13 |
| JIS | SUS347 | SUS347H |
Types of Stainless Steel 347 / 347H Bolts Available
Different industrial applications require specialized bolt configurations based on structural and assembly requirements.
Bolt Type
| Bolt Type | Applications |
|---|---|
| Hex Head Bolts | Industrial assemblies |
| Square Bolts | Structural fabrication |
| U Bolts | Pipe support systems |
| Eye Bolts | Lifting systems |
| T Bolts | Mechanical assemblies |
| Lag Bolts | Heavy structural mounting |
| Countersunk Bolts | Flush installations |
| J Bolts | Foundation systems |
| Allen Bolts | Precision assemblies |
| Shoulder Bolts | Mechanical components |
Available Thread Options
| Thread Type | Availability |
|---|---|
| UNC Threads | Available |
| UNF Threads | Available |
| Metric Threads | Available |
| BSW Threads | Available |
| BSF Threads | Available |
| Fine Threads | Available |
| Custom Thread Configurations | Available |
Stainless Steel 347 vs Stainless Steel 347H Bolts Comparison
Both Stainless Steel 347 Bolts & 347H Bolts are niobium stabilized stainless steel grades developed for applications requiring high temperature resistance, excellent corrosion protection, and reliable performance after welding. The main difference between both grades is carbon content, which influences high temperature mechanical performance and creep strength.
| Property | SS 347 Bolts | SS 347H Bolts |
|---|---|---|
| UNS Number | S34700 | S34709 |
| Carbon Content | Max 0.08% | Higher Carbon Content |
| Temperature Resistance | High | Very High |
| Creep Strength | Good | Better |
| Weldability | Excellent | Excellent |
| Oxidation Resistance | Very Good | Excellent |
| Typical Applications | Heat Exchangers, Chemical Plants | Furnaces, Pressure Vessels |
| Best Use | General High Temperature Service | Continuous Elevated Temperature Service |
For general thermal processing systems, SS 347 Bolts are widely preferred because of excellent corrosion resistance and welded structural stability. For prolonged elevated temperature applications, SS 347H Bolts provide improved creep resistance and long-term performance. Industrial buyers often compare SS 321 Bolts for titanium stabilized high temperature applications, while SS 316 Bolts are widely selected for corrosion resistant marine and chemical processing systems.
Stainless Steel 347 Bolts Suppliers in Europe for Chemical & Thermal Processing Applications
European industrial sectors use SS 347 and SS 347H Bolts extensively in petrochemical systems, industrial heating units, pressure vessels, refinery equipment, and chemical processing plants where corrosion resistance and elevated temperature stability are critical for long-term operational reliability.
Aurum Overseas exports certified stainless steel bolting solutions to Germany, France, Italy, Spain, Netherlands, Belgium, and other European industrial markets with full inspection certification and export compliance documentation.
Stainless Steel 347 Bolts Exporters in USA for Refinery & High Temperature Engineering Applications
Industrial manufacturers in the United States require reliable stainless steel fastening systems for pressure vessels, heat exchangers, refinery units, aerospace components, and industrial furnace systems operating under elevated temperatures. Stainless steel 347 series bolts are widely specified because of their excellent thermal stability and weld integrity.
Aurum Overseas supplies certified stainless steel fastening solutions across the USA with complete material traceability, third-party inspection support, and international export packaging for industrial procurement requirements.
Stainless Steel 347 Bolts Suppliers in Gulf Countries for Petrochemical & Energy Projects
The Gulf region requires corrosion resistant and heat resistant fastening solutions for refinery systems, offshore engineering projects, petrochemical plants, power generation facilities, and industrial processing systems exposed to aggressive service conditions and elevated temperatures.
Aurum Overseas exports stainless steel bolting solutions throughout UAE, Saudi Arabia, Qatar, Kuwait, Oman, and Bahrain with project-based manufacturing support, international quality certifications, and dependable export logistics.
Industries Using Stainless Steel 347 Series Bolting Solutions
These stainless steel fastening solutions are widely used across industries requiring thermal stability and corrosion resistance.
| Industry | Applications |
|---|---|
| Petrochemical | Reactor assemblies |
| Refineries | Pressure vessel fastening |
| Power Generation | Boiler systems |
| Heat Exchangers | High temperature assemblies |
| Chemical Processing | Corrosion resistant piping |
| Aerospace | Exhaust systems |
| Furnace Manufacturing | Thermal chambers |
| Industrial Heating | Combustion systems |
| Offshore Engineering | Structural fastening |
| Heavy Engineering | Industrial fabrication |
Why Industrial Buyers Choose Aurum Overseas for Stainless Steel Fastening Solutions
Aurum Overseas supplies industrial fastening solutions engineered for demanding environments where corrosion resistance, structural strength, and long-term performance directly affect operational reliability. We work with EPC contractors, engineering companies, industrial procurement teams, and global distributors requiring certified fastening materials for critical industrial applications.
Our quality systems, manufacturing capability, export expertise, and technical support allow us to serve industrial customers across global markets with reliable fastening solutions.
- Certified Material Test Certificates
- Custom Manufacturing Support
- Bulk Production Capability
- Third Party Inspection
- International Export Packaging
- Fast Worldwide Delivery
- Competitive Industrial Pricing
- Full Material Traceability
Frequently Asked Questions
1. What is Stainless Steel 347?
Stainless Steel 347 is a niobium stabilized austenitic stainless steel designed for applications
involving elevated temperatures and welded structures. The niobium addition improves resistance against
carbide precipitation and intergranular corrosion.
2. What is UNS S34709?
UNS S34709 is the official material designation for Stainless Steel 347H designed for industrial
applications requiring improved high temperature strength during continuous thermal exposure.
3. What is the difference between SS 347 and SS 347H Bolts?
The primary difference is carbon content. SS 347H Bolts contain higher carbon which improves creep
strength and mechanical stability during prolonged high temperature service compared to standard SS 347.
4. Why is Niobium Added in Stainless Steel 347?
Niobium stabilizes the alloy and prevents chromium carbide precipitation during welding or high
temperature exposure. This improves corrosion resistance and long-term structural reliability.
5. Do You Export Stainless Steel 347 Bolts to European Countries?
Yes. Aurum Overseas exports certified stainless steel 347 series bolting solutions across European
industrial markets with complete inspection certificates and international export documentation.
6. Can You Manufacture Custom Stainless Steel Bolts?
Yes. We manufacture custom stainless steel bolts in special thread configurations, non-standard
dimensions, custom lengths, and project-specific engineering drawings according to industrial
requirements.
Request Technical Support & Pricing
Choosing the right fastening material directly affects long-term equipment reliability, corrosion resistance, operational safety, and mechanical performance. Aurum Overseas supplies certified industrial bolting solutions manufactured according to international quality standards for demanding engineering applications worldwide.
Our technical team supports procurement managers, EPC contractors, industrial buyers, distributors, and engineering companies with product selection guidance, custom manufacturing support, technical documentation, bulk pricing, and global export solutions for industrial projects.
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