Elevated-Temperature Strength
304H and 347H provide controlled carbon levels for improved creep and stress-rupture performance at elevated temperatures.
Specialty Alloy Fasteners
Specialty Austenitic Stainless Steel Fasteners Manufacturer
High-performance stainless steel bolts, stud bolts and custom fasteners engineered for elevated-temperature, stabilized and high-strength industrial applications.
Specialized Austenitic Grade Expertise
304H, 304N, 316Ti, 321, 347 and 347H fasteners for demanding service conditions.
High-Temperature & Stabilized Performance
Controlled carbon, nitrogen, titanium or niobium provides grade-specific strength and stability.
Custom Manufacturing
Standard and drawing-based stainless steel fasteners manufactured to project-specific dimensions and requirements.
Overview
Specialty Austenitic Stainless Steel for Demanding Applications
This material group combines several specialized austenitic stainless steel grades developed for different elevated-temperature, corrosion and strength requirements. 304H and 347H contain controlled higher carbon levels to improve creep and stress-rupture strength at elevated temperatures. 304N uses nitrogen alloying to provide higher strength than conventional 304 and is not a stabilized grade. 321 and 316Ti use titanium stabilization, while 347 and 347H use niobium stabilization. These additions reduce susceptibility to intergranular corrosion after welding or prolonged exposure within sensitizing temperature ranges. Because these grades use different strengthening and stabilization mechanisms, the exact material designation, condition and governing specification must be confirmed for each project.
Why Choose This Material
Why Specialized Austenitic Stainless Steel Is Selected for Critical Fastening Applications
These grades provide elevated-temperature strength, intergranular-corrosion resistance and specialized mechanical performance for demanding industrial fastening systems.
Intergranular Corrosion Resistance
Titanium- or niobium-stabilized grades reduce susceptibility to intergranular corrosion after welding and elevated-temperature exposure.
Nitrogen-Strengthened Performance
304N uses nitrogen alloying to increase yield strength while retaining useful corrosion resistance and ductility.
Flexible Grade Selection
Different grades allow engineers to select the required balance of temperature capability, corrosion resistance and mechanical strength.
Specialty Austenitic Stainless Steel Grades Available for Fasteners
304H, 304N, 316Ti, 321, 347 and 347H provide different combinations of elevated-temperature strength, stabilization and corrosion resistance.
304H Stainless Steel
UNS:
S30409
EN / W.Nr.:
1.4948
ASTM A965 Forging Grade:
F304H
Standards
- ASTM A479
- ASTM A965 F304H
Characteristics
- Controlled carbon for elevated-temperature strength
- Good creep and stress-rupture performance
- Good high-temperature oxidation resistance
Applications
Boilers, Heat exchangers, Pressure vessels, High-temperature equipment
304N Stainless Steel
UNS:
S30451
EN / W.Nr.:
1.4315
ASTM A965 Forging Grade:
F304N
Standards
- ASTM A479
- ASTM A965 F304N
Characteristics
- Nitrogen-strengthened 304 grade
- Higher yield strength than standard 304
- Good general corrosion resistance
Applications
Pressure equipment, Structural components, High-load fasteners, Industrial equipment
316Ti Stainless Steel
UNS:
S31635
EN / W.Nr.:
1.4571
Standards
- ASTM A276
- ASTM A479
- EN 10088-3
Characteristics
- Titanium-stabilized Cr-Ni-Mo grade
- Good intergranular corrosion resistance
- Improved chloride resistance over 304 grades
Applications
Chemical processing, Flue gas systems, Heat exchangers, Flanges & valves
321 Stainless Steel
UNS:
S32100
EN / W.Nr.:
1.4541
ASTM A965 Forging Grade:
F321
Standards
- ASTM A276
- ASTM A479
- ASTM A965 F321
Characteristics
- Titanium-stabilized austenitic grade
- Good intergranular corrosion resistance
- Good elevated-temperature performance
Applications
Heat exchangers, Furnace components, Exhaust systems, Chemical equipment
347 Stainless Steel
UNS:
S34700
EN / W.Nr.:
1.4550
ASTM A965 Forging Grade:
F347
Standards
- ASTM A276
- ASTM A479
- ASTM A965 F347
Characteristics
- Niobium-stabilized austenitic grade
- Good intergranular corrosion resistance
- Good high-temperature mechanical properties
Applications
Chemical equipment, Expansion joints, Exhaust systems, Flanges & valves
347H Stainless Steel
UNS:
S34709
EN / W.Nr.:
1.4912
ASTM A965 Forging Grade:
F347H
Standards
- ASTM A276
- ASTM A479
- ASTM A965 F347H
Characteristics
- Controlled higher carbon content
- Improved creep and stress-rupture strength
- Niobium-stabilized microstructure
Applications
Boilers, Superheaters, Refineries, High-temperature pressure equipment
Other Specialized Austenitic Grades Available
Additional high-temperature, stabilized and nitrogen-strengthened grades can be reviewed according to project specifications and service requirements.
Chemical Composition of Specialty Austenitic Stainless Steel
Compare the principal alloying elements and stabilization mechanisms that influence strength, corrosion resistance and elevated-temperature performance.
| GRADE | C (%) | CR (%) | NI (%) | MO (%) | N (%) | STABILIZING ELEMENT (%) | OTHER (%) |
|---|---|---|---|---|---|---|---|
| 304H / S30409 | 0.04–0.10 | 18.0–20.0 | 8.0–10.5 | — | — | — | Mn 2.00 max, Si 1.00 max |
| 304N / S30451 | 0.08 max | 18.0–20.0 | 8.0–12.0 | — | 0.10–0.16 | — | Mn 2.00 max, Si 1.00 max |
| 316Ti / S31635 | 0.08 max | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 | 0.10 max | Ti: 5×(C+N) min, 0.70 max | Mn 2.00 max, Si 1.00 max |
| 321 / S32100 | 0.08 max | 17.0–19.0 | 9.0–12.0 | — | — | Ti: 5×(C+N) min, 0.70 max | Mn 2.00 max, Si 1.00 max |
| 347 / S34700 | 0.08 max | 17.0–19.0 | 9.0–12.0 | — | — | Nb: 10×C min, 1.10 max | Mn 2.00 max, Si 1.00 max |
| 347H / S34709 | 0.04–0.10 | 17.0–19.0 | 9.0–12.0 | — | — | Nb: 8×C min, 1.10 max | Mn 2.00 max, Si 1.00 max |
Reference values are provided for general comparison only. The governing material specification and batch MTC take precedence for production and acceptance.
Mechanical Performance of Specialty Austenitic Stainless Steel
These grades provide different combinations of room-temperature strength, ductility and elevated-temperature performance according to their alloy design.
| GRADE / CONDITION | TENSILE STRENGTH (MPa) | 0.2% YIELD STRENGTH (MPa) | ELONGATION (%) |
|---|---|---|---|
| 304H — Annealed Bar Reference | 515 min | 205 min | 30 min |
| 304N — Annealed Bar Reference | 550 min | 240 min | 30 min |
| 316Ti — Annealed Bar Reference | 515 min | 205 min | 30 min |
| 321 — Annealed Bar Reference | 515 min | 205 min | 30 min |
| 347 — Annealed Bar Reference | 515 min | 205 min | 30 min |
| 347H — Annealed Bar Reference | 515 min | 205 min | 30 min |
Mechanical properties depend on product form, dimensions, material condition, heat treatment and the applicable specification. The purchase specification and actual inspection certificate shall govern the order.
Specialty Austenitic Stainless Steel Grade Selection Guide
Choose the grade according to temperature, stabilization method, corrosion environment and required mechanical strength.
| Application Requirement | Recommended Grade |
|---|---|
| General elevated-temperature service | 304H |
| Improved creep strength in a 304-type composition | 304H |
| Higher yield strength through nitrogen alloying | 304N |
| Nitrogen-strengthened pressure equipment | 304N |
| Molybdenum alloying with titanium stabilization | 316Ti |
| Chloride exposure with stabilization required | 316Ti |
| Titanium-stabilized high-temperature service | 321 |
| Niobium-stabilized corrosion resistance | 347 |
| Elevated-temperature niobium-stabilized service | 347H |
| Boilers, superheaters and refinery equipment | 347H |
| Severe chloride or highly corrosive service | Evaluate Duplex, Super Duplex or Super Austenitic grades |
Specialty Austenitic Stainless Steel Fastener Product Range
Specialized stainless steel fasteners are available in standard and custom configurations for thermal, chemical, pressure-equipment and industrial applications.
Hex Bolts
Product Type: Hex Head Bolts / Full Thread Hex Bolts / Partial Thread Hex Bolts / Custom Hex Bolts
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Heavy Hex Bolts
Product Type: Heavy Hex Bolts / Large Diameter Heavy Hex Bolts / Custom Heavy Hex Bolts
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Stud Bolts
Product Type: Fully Threaded Studs / Double End Studs / Tap End Studs / Flange Stud Sets
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF / 8UN
Thread Type: Coarse / Fine
Standard: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Nuts
Product Type: Hex Nuts / Heavy Hex Nuts / Custom Nuts
Size Range: Matched to Bolt / Stud Size
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Washers
Product Type: Flat Washers / Heavy Washers / Custom Washers
Size Range: Standard / Custom
Inner Diameter: Standard / Custom
Outer Diameter: Standard / Custom
Thickness: Standard / Custom
Standard: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Socket Head Cap Screws
Product Type: Socket Head Cap Screws / Custom Socket Screws
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Threaded Rods
Product Type: Fully Threaded Rods / Cut-to-Length Threaded Rods
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Custom Components
Product Type: Custom Bolts / Special Studs / Threaded Parts / Machined Components
Size Range: According to Drawing
Tolerance: According to Drawing
Manufacturing Basis: Customer Drawing / Project Specification
Inspection: Dimensional / PMI / Mechanical Testing as Required
Need a Product Type Not Shown Here?
We also manufacture custom and project-specific fasteners according to drawings, specifications or application requirements.
Process Control
Manufacturing Excellence
A controlled six-stage production workflow supports consistent manufacturing from reviewed raw material to finished, identified and export-ready specialty-alloy fasteners.
01
Raw Material Preparation
The specified alloy grade, product form, material condition and batch identity are reviewed before cutting. Stock is prepared according to the order and selected manufacturing route.
02
Cutting & Blanking
Bars, rods or forgings are cut to the required blank size while maintaining material separation and batch identification.
03
Forging / CNC Machining
Headed fasteners are forged and machined when appropriate, while complex, low-volume or drawing-based components can be produced by precision CNC machining.
04
Thread Manufacturing
Threads are rolled or cut according to material condition, product geometry, dimensional standard and customer requirements.
05
Heat Treatment
Solution treatment, annealing, age hardening or other thermal processing is applied only when required by the alloy grade, material condition and governing specification.
06
Finishing & Packing
Finished parts are deburred, cleaned and prepared as specified, then identified and packed according to order and traceability requirements.
Quality Control
Quality Assurance & Full Traceability
Inspection and documentation are planned around the purchase specification, customer drawing and intended service. The agreed inspection scope is confirmed according to individual project requirements.
Material Verification
Material grade, heat or lot number and incoming documents are checked against the agreed order requirements before production.
Heat Number Traceability
Batch identity is maintained through production, inspection and packing so finished parts can be linked to their source material.
Dimensional Inspection
Critical dimensions, tolerances and product geometry are checked against the applicable dimensional standard or customer drawing.
Thread Inspection
Thread size, pitch and fit are verified using suitable gauges and measuring equipment. Additional profile verification can be arranged when specified.
PMI & Mechanical Testing
PMI, hardness, tensile or other testing can be performed or arranged when specified, depending on the material, test method and project requirements.
MTC / EN 10204 3.1 Documentation
MTC / EN 10204 3.1 documentation, dimensional reports, PMI reports and traceability records can be supplied when specified and applicable.
Inspection methods, sampling plans, acceptance criteria and document requirements should be confirmed before order placement.
Discuss Inspection & Documentation RequirementsIndustries Served
Applications & Industries
Our specialty-alloy fasteners support demanding projects across multiple industries. Final material selection must be based on the actual temperature, corrosion medium, mechanical load, applicable standards and required service life.
Oil & Gas
Flange bolting, valves, pressure equipment, piping systems and process units exposed to pressure, temperature or corrosive media.
Chemical Processing
Reactors, heat exchangers, scrubbers, pumps and equipment handling acids, chlorides or other aggressive process media.
Power Generation
Gas and steam turbines, boilers, furnaces, heat-treatment systems and high-temperature mechanical assemblies.
Marine & Offshore
Offshore platforms, seawater systems, marine equipment and desalination installations requiring corrosion-resistant fastening.
Aerospace
Engine, thermal and precision assemblies requiring high strength, temperature capability, low weight or controlled material performance.
Nuclear & Critical Equipment
Safety-critical bolting and engineered components requiring controlled materials, documentation and reliable long-term performance.
Not every alloy is suitable for every industry or service condition. Material suitability should be confirmed against the governing specification and actual operating environment.
Discuss Your ApplicationFrequently Asked Questions
Common questions about specialty-alloy fasteners, custom manufacturing, standards, inspection, documentation and procurement.
1. What specialty-alloy fastener products can you manufacture?
Our product range includes hex bolts, heavy hex bolts, stud bolts, nuts, washers, socket head cap screws, threaded rods and drawing-based fasteners or machined components. Availability depends on material grade, dimensions and quantity.
2. Can you manufacture non-standard parts from customer drawings?
Yes. We can review drawings for custom bolts, studs, nuts, washers, threaded parts and precision machined components. The quotation is based on material, dimensions, tolerances, heat treatment, inspection requirements and order quantity.
3. Which dimensional and thread standards can you support?
Products can be manufactured to applicable ISO, DIN, ASME and other recognized dimensional standards, or to customer drawings. Metric, UNC, UNF and other thread systems can be evaluated according to the product and specification.
4. Can you provide MTC and EN 10204 3.1 documentation?
Material test certificates and EN 10204 3.1 documentation can be supplied when specified and applicable to the ordered material and product. Certificate requirements should be confirmed before order placement.
5. Is PMI or third-party inspection available?
PMI and third-party inspection can be arranged when required. The test method, sampling plan, acceptance criteria and reporting requirements should be defined before production.
6. How do you maintain material traceability?
Heat or lot identification is maintained from incoming material through production, inspection and packing, subject to the agreed order and documentation requirements.
7. Can you supply bolts, nuts and washers as matched bolting sets?
Yes. Complete bolting sets can be supplied when requested, with thread compatibility, material selection, inspection and packaging defined for the order.
8. What are your MOQ and lead time?
MOQ and lead time depend on alloy grade, raw-material availability, product size, manufacturing route, heat treatment, testing and order quantity. Made-to-order specialty-alloy fasteners normally require a technical review before confirmation.
Request for Quotation
Custom & Standard
Specialty Austenitic Stainless Steel Fasteners,
Direct From
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Send us your Specialty Austenitic Stainless Steel fastener specifications, standards or drawings. Our engineering team will review your requirements and provide a detailed project-specific quotation.
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