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Alloy 20 Washers Suppliers & Exporters
If your sulfuric acid systems or synthetic rubber plants require superior resistance to acid corrosion, you've reached the right source. As a premier Alloy 20 Washers Supplier and Exporter, Aurum Overseas manufactures precision fasteners to ASME B18.21.1, DIN 125, and ISO 7089 standards.
Our Carpenter 20 Washers and UNS N08020 Washers feature an Fe-Ni-Cr matrix alloyed with copper, molybdenum, and niobium stabilization for immunity against sulfuric acid up to 500°C (932°F). Supplied with full EN 10204 3.1 MTR certifications, our complete stock of Alloy 20 fasteners is ready for immediate global dispatch.
We export these washers 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).
Technical Specifications
| Parameter | Technical Specification / Standard Range |
|---|---|
| Material Grade | Alloy 20 / Carpenter 20 CB-3 |
| Forging Specification | ASTM B473 / ASME SB473 |
| UNS Designation | UNS N08020 |
| Manufacturing Standards | ASTM B463, ASME SB463, ASTM B473, ASME SB473 |
| Dimensional Specifications | ASME B18.21.1, DIN 125 A/B, DIN 127, DIN 9021, ISO 7089, ISO 7090 |
| Washer Types | Plain Washers, Spring Washers, Lock Washers, Square Washers, Conical Washers |
| Size Capability | Imperial: #4 to 4" NB | Metric: M3 to M100 |
| Thickness Range | 0.5 mm to 12 mm |
| Hardness Limit | 95 HRB max / 217 HB max |
Technical Properties & Chemical Composition
Equivalent Grades of Alloy 20 Washers
| STANDARD | WERKSTOFF NR. | UNS |
|---|---|---|
| Alloy 20 | 2.4660 | N08020 |
Chemical Composition of Alloy 20 Washers
| Element | Composition (%) |
|---|---|
| Nickel (Ni) | 32.00 – 38.00 |
| Chromium (Cr) | 19.00 – 21.00 |
| Iron (Fe) | 29.85 min* |
| Copper (Cu) | 3.00 – 4.00 |
| Molybdenum (Mo) | 2.00 – 3.00 |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 1.00 max |
| Carbon (C) | 0.07 max |
| Phosphorus (P) | 0.045 max |
| Sulfur (S) | 0.035 max |
Mechanical & Physical Properties of Alloy 20 Washers
| Property | Metric Value | Imperial Value |
|---|---|---|
| Ultimate Tensile Strength | 551 MPa min | 80,000 psi min |
| Yield Strength (0.2% Offset) | 241 MPa min | 35,000 psi min |
| Elongation (%) | 30% min | 30% min |
| Density | 8.10 g/cm³ | 0.292 lb/in³ |
| Melting Point | 1443°C | 2430°F |
Types of Alloy 20 Washers
Aurum Overseas supplies a comprehensive range of Alloy 20 washer configurations manufactured according to standard DIN, ASME, and ISO dimensional tolerances for multiple engineering assemblies.
Alloy 20 Plain Washers
Alloy 20 Spring Washers
Alloy 20 Lock Washers
Alloy 20 Square Washers
Alloy 20 Conical Washers
Key Advantages
Sulfuric Acid Resistance
Copper addition (3.00–4.00%) provides unmatched stability in hot, medium-concentration sulfuric acid processes.
Columbium (Niobium) Stabilization
Prevents intergranular corrosion and chromium carbide precipitation during welding and high-temperature thermal cycling.
Chloride Stress Cracking Protection
Elevated nickel content (32.00–38.00%) minimizes risk of stress-corrosion cracking in chloride and acid vapor environments.
Pitting and Crevice Corrosion Defense
Molybdenum content (2.00–3.00%) offers targeted protection against severe localized pitting in acid-chloride solutions.
Key Applications of Alloy 20 Washers
| Industry Sector | Application | Operating Environment |
|---|---|---|
| Chemical Manufacturing | Sulfuric acid pickling tanks, mixing vats, heat exchangers, and chemical piping | Hot sulfuric acid (20% – 40%), phosphoric acid, and nitrating chemicals |
| Pharmaceuticals & Synthetics | Synthetic rubber processing equipment, reactor vessel covers, and process pumps | Aggressive organic reactions and acidic solvent recovery systems |
| Food & Beverage Processing | Acid cleaning equipment, sanitation loops, and process mixing bolting | Concentrated food acids, CIP chemicals, and hot chloride washdown solutions |
| Plastics & Petrochemicals | Polymer production flanges, acid mist scrubbers, and valve body bolting | Acid gas condensation, sulfuric acid streams, and hydrocarbon processing |
| Pulp & Paper Operations | Digester fasteners, bleaching section bolting, and liquor tank seals | Chlorine dioxide, sulfur dioxide gas, and acidic bleaching liquors |
Quality Testing & Inspection
- Positive Material Identification (PMI): X-ray fluorescence analysis checks element ratios (Ni, Cr, Cu, Mo, Nb).
- Mechanical & Hardness Testing: Tensile, yield, and Rockwell hardness verification per ASTM B473 requirements.
- Intergranular Corrosion Test: Evaluation according to ASTM A262 Practice E ensures optimal stabilization.
- Dimensional Inspection: Optical comparator checks ensure strict dimensional control for inner diameter, outer diameter, and thickness tolerances.
Global Export Markets
Aurum Overseas supplies fully certified Alloy 20 Washers to industrial projects across:
USA
Canada
Mexico
Germany
United
Kingdom
France
Italy
Netherlands
Norway
UAE
Saudi
Arabia
Qatar
Kuwait
Oman
Singapore
Malaysia
Australia
Frequently Asked Questions
Alloy 20 contains higher nickel and copper levels specifically balanced to resist sulfuric acid attack, where standard 304 or 316 grades suffer rapid degradation.
Niobium acts as a stabilizer by forming stable carbides, preventing intergranular chromium depletion during heat exposure and welding operations.
Yes. With 32–38% nickel and 2–3% molybdenum, Alloy 20 offers strong resistance to chloride stress-corrosion cracking and localized pitting.
Alloy 20 maintains mechanical stability and corrosion resistance up to continuous operating temperatures of approximately 500°C (932°F).
Every shipment includes EN 10204 3.1 MTR documentation verifying full chemical analysis, mechanical property testing, and PMI inspection results.
Contact Aurum Overseas
Aurum Overseas provides rapid delivery of certified Alloy 20 Washers for high-specification global infrastructure.
Contact our sales engineering team for technical assistance, material certifications, and rapid pricing.