Table of Contents
- SS 304/304L/304H Washers Overview
- SS 304/304L/304H Washers Specifications
- Technical Properties & Chemical Composition
- Grades Comparison: SS 304 vs. SS 304L vs. SS 304H
- Why Industries Prefer SS 304/304L/304H Washers
- Types of SS 304 Washers
- Key Technical Advantages
- Key Applications of SS 304/304L/304H Washers
- Quality Assurance & Mechanical Testing
- Global Export Markets
- Frequently Asked Questions
- Contact Aurum Overseas
SS 304/304L/304H Washers Suppliers & Exporters
Aurum Overseas is a premier SS 304/304L/304H Washers Supplier and SS 304/304L/304H Washers Exporter, providing high-performance 18-8 austenitic stainless steel washers engineered for uniform load distribution and leak-free flange seals.
Manufactured in full compliance with ASME B18.21.1 and DIN 125 standards, these specialized UNS S30400 / S30403 / S30409 Washers deliver exceptional resistance to atmospheric oxidation, chemical attack, and galling across chemical processing, power generation, and sanitary piping systems.
As a worldwide SS 304/304L/304H Washers Exporter, Aurum Overseas distributes fully certified and traceable bolting hardware across North America (USA, Canada, Mexico), Europe (Germany, UK, France, Italy, Netherlands, Norway), the Middle East (UAE, Saudi Arabia, Qatar, Kuwait, Oman), and Asia-Pacific (Singapore, Malaysia, Australia).
SS 304/304L/304H Washers Specifications
| Parameter | Technical Specification / Standard Range |
|---|---|
| Material Grades | Stainless Steel 304, 304L, 304H |
| UNS Designations | UNS S30400 / S30403 / S30409 Washers |
| Werkstoff Numbers | 1.4301 / 1.4306 / 1.4307 |
| Manufacturing Standards | ASTM A240 / ASME SA240, ASTM F844, ASTM A193/A194 Hardware Specs |
| Dimensional Specifications | ASME B18.21.1, DIN 125 A/B, DIN 127 B, DIN 9021, ISO 7089, ISO 7090 |
| Washer Types | Plain Flat, Heavy Duty Flat, Spring Lock, Belleville Washers, Square Washers, Tab Washers |
| Size Range | Imperial: #4 to 4" NB | Metric: M3 to M100 |
| Thickness Range | 0.5 mm to 12 mm (Custom gauges available on order) |
| Hardness Range | Annealed: HRB 92 max (201 HBW max) | Quarter Hard / Half Hard options |
| Surface Finishes | Bright Annealed, Passivated, Pickled, Electro-polished, PTFE/Xylan Coated |
| Certification | EN 10204 3.1 MTR, PMI Testing Report, Hardness Verification |
Technical Properties & Chemical Composition
Equivalent Material Standards
| Standard / System | SS 304 | SS 304L | SS 304H |
|---|---|---|---|
| UNS Designation | S30400 | S30403 | S30409 |
| Werkstoff Nr. | 1.4301 | 1.4306 / 1.4307 | 1.4301 |
| EN Standard | X5CrNi18-10 | X2CrNi18-9 / X2CrNi19-11 | — |
Chemical Composition (%)
| Element | SS 304 | SS 304L | SS 304H |
|---|---|---|---|
| Carbon (C) | 0.08 max | 0.030 max | 0.04 – 0.10 |
| Manganese (Mn) | 2.00 max | 2.00 max | 2.00 max |
| Silicon (Si) | 0.75 max | 0.75 max | 0.75 max |
| Phosphorus (P) | 0.045 max | 0.045 max | 0.045 max |
| Sulfur (S) | 0.030 max | 0.030 max | 0.030 max |
| Chromium (Cr) | 18.0 – 20.0 | 18.0 – 20.0 | 18.0 – 20.0 |
| Molybdenum (Mo) | — | — | — |
| Nickel (Ni) | 8.0 – 10.5 | 8.0 – 12.0 | 8.0 – 10.5 |
| Nitrogen (N) | 0.10 max | 0.10 max | — |
Mechanical Properties
| Property / Parameter | SS 304 | SS 304L | SS 304H |
|---|---|---|---|
| Tensile Strength (MPa) min | 515 | 485 | 515 |
| Yield Strength 0.2% Proof (MPa) min | 170 | 170 | 205 |
| Elongation (% in 50mm) min | 40 | 40 | 40 |
| Rockwell Hardness B (HR B) max | 92 | 92 | 92 |
| Brinell Hardness (HB) max | 201 | 201 | 201 |
Grades Comparison: SS 304 vs. SS 304L vs. SS 304H
| Feature | SS 304 | SS 304L | SS 304H |
|---|---|---|---|
| Carbon Content | Standard (0.08% max) | Low (0.030% max) | Controlled High (0.04% - 0.10%) |
| Max Service Temp. | Up to 800°C (1472°F) | Up to 425°C (800°F) | Continuous service above 500°C up to 800°C |
| Weld Heat Zone | Susceptible to sensitization | Prevents intergranular decay | Optimized for creep strength |
| Grain Structure | Standard commercial | Fine grain toughness | Mandatory ASTM No. 7 or coarser |
| Best Used For | Standard industrial bolting | Heavy-gauge welded assemblies | High-temp boilers & pressure vessels |
Why Industries Prefer SS 304/304L/304H Washers
Prevents Surface Deformation: Spreads high thread torque loads across joint faces to eliminate crushing or scoring on softer mating materials.
Maintains Flange Preload Integrity: Resists stress relaxation under fluctuating operating pressures to guarantee leak-free gasket seals.
Resists Corrosion & Oxidation: Austenitic chromium-nickel chemistry prevents atmospheric rust, nitric acid attack, and chemical degradation.
Prevents Thermal Creep Rupture: High-carbon 304H variants maintain structural elasticity and prevent sagging in high-temperature systems up to 800°C.
Eliminates Weld-Zone Corrosion: Low-carbon 304L variants allow direct welding of washer assemblies without intergranular decay.
Types of SS 304 Washers
Aurum Overseas supplies a comprehensive range of stainless steel washer configurations manufactured according to standard DIN, ASME, and ISO dimensional tolerances for multiple engineering assemblies.
SS 304 Plain Washers
SS 304 Spring Washers
SS 304 Lock Washers
SS 304 Square Washers
SS 304 Conical Washers
Key Technical Advantages
High Ductility & Toughness
Maintains impact strength down to cryogenic temperatures without brittle transition risks.
Non-Magnetic Behavior
Fully austenitic structure provides low magnetic permeability in electronic, medical, and power distribution systems.
Precision Surface Flatness
Cold-stamped and deburred tolerances prevent uneven clamping stress and gasket punch-through.
Passivated Anti-Galling Finish
Chemical passivation cleans free iron contamination, enhancing passive chromium oxide protection.
Versatile Coating Compatibility
Accommodates PTFE, Xylan, and silver plating for friction management and galling prevention.
Key Applications of SS 304/304L/304H Washers
| Industry Sector | Recommended Grade | Typical Equipment Application | Service Conditions |
|---|---|---|---|
| Chemical Processing | SS 304L | Storage tanks, piping flanges, mixing vessels | Nitric acid, welded joints |
| Power & Boilers | SS 304H | Superheater headers, heat exchangers | Temps > 500°C, thermal cycling |
| Food & Pharma | SS 304 | Processing lines, sanitary pumps | CIP washdowns, hygienic joints |
| Oil & Gas | SS 304 / 304L | Distillation columns, utility lines | Hydrocarbons, atmospheric exposure |
| Water Treatment | SS 304 | Desalination pre-treatment, pump skids | High moisture, chlorinated effluent |
Quality Assurance & Mechanical Testing
As a dedicated SS 304/304L/304H Washers Supplier and SS 304/304L/304H Washers Exporter, Aurum Overseas subjects every manufacturing lot to comprehensive quality verification before shipment.
- Chemical Verification: Positive Material Identification (PMI) via XRF spectroscopy to verify exact chromium, nickel, and carbon purity limits.
- Mechanical & Hardness Testing: Proof load, yield strength, and Rockwell B hardness verification (<= 92 HRB) per ASTM A240 standards.
- Dimensional Precision: Optical comparator and digital micrometer inspection for thickness, inner clearance, and outer diameter tolerances per ASME B18.21.1 and DIN 125.
- Material Traceability: Complete EN 10204 3.1 Material Test Reports provided with every order, detailing full heat source and batch test results.
Global Export Markets
Aurum Overseas distributes UNS S30400 / S30403 / S30409 Washers to key industrial hubs and major engineering projects worldwide:
USA
Canada
Mexico
Germany
United
Kingdom
France
Italy
Netherlands
Norway
UAE
Saudi
Arabia
Qatar
Kuwait
Oman
Singapore
Malaysia
Australia
Frequently Asked Questions
SS 304 is the standard general-purpose grade. SS 304L has a lower carbon limit (0.030% max) to prevent intergranular corrosion in welded joints. SS 304H features controlled higher carbon (0.04–0.10%) and coarser grain size for high-temperature service.
Specify UNS S30403 washers when the bolting assembly involves direct welding or exposure to chemical environments where post-weld sensitization could cause joint corrosion.
SS 304H contains higher carbon and requires an ASTM No. 7 or coarser grain structure, offering higher creep strength and stress-rupture resistance at operating temperatures above 500°C.
In the fully annealed condition, these austenitic stainless steel washers are non-magnetic. Mild magnetism may develop after cold stamping or cold working, which can be removed via solution annealing if required.
We manufacture washers to standard imperial and metric dimensions including ASME B18.21.1, DIN 125, DIN 127, DIN 9021, and ISO 7089, as well as custom drawings.
Yes, as a global SS 304/304L/304H Washers Exporter, Aurum Overseas supplies fully certified washers with EN 10204 3.1 Material Test Reports to customers worldwide.
Contact Aurum Overseas
Aurum Overseas manufactures and stocks certified SS 304/304L/304H Washers for immediate global dispatch.
Contact our technical sales team for instant pricing, material test reports, and custom size requirements.