Table of Contents
- SS 317L Washers Overview
- SS 317L Washers Specifications
- SS 317L Technical Properties & Chemical Composition
- Comparison: SS 317L vs. SS 316L
- Why Heavy Process Industries Specify SS 317L Washers
- Types of SS 317L Washers
- Key Technical Advantages
- Key Applications of SS 317L Washers
- Quality Testing & Inspection Standards
- Global Export Markets
- Frequently Asked Questions
- Contact Aurum Overseas
SS 317L Washers Suppliers & Exporters
Aurum Overseas is an established SS 317L Washers Supplier and SS 317L Washers Exporter, stocking high-molybdenum molybdenum-chromium-nickel austenitic stainless steel washers engineered for aggressive acid processing systems and high-chloride marine environments.
Manufactured in strict accordance with dimensional standards such as ASME B18.21.1, DIN 125, DIN 127, and ISO 7089, these ASTM A240 UNS S31703 Washers incorporate a elevated 3.0% – 4.0% molybdenum chemical addition. This specific alloying ratio provides enhanced resistance to pitting, crevice corrosion, and intergranular sensitization compared to standard 316-grade hardware.
As a trusted global SS 317L Washers Exporter, Aurum Overseas supplies fully certified UNS S31703 Washers to critical process infrastructure 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 317L Washers Specifications
| Parameter | Technical Specification / Standard Range |
|---|---|
| Material Grade | Stainless Steel 317L (Low Carbon) |
| UNS Designation | UNS S31703 |
| Werkstoff Number | 1.4438 |
| Euronorm Standard | X2CrNiMo18-15-4 |
| Material Specifications | ASTM A240 / ASME SA240, 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 Washers, Heavy Duty Structural, Spring Lock, Belleville Washers, Square Washers |
| Size Range | Imperial: #4 to 4" NB | Metric: M3 to M100 |
| Thickness Range | 0.5 mm to 12 mm (Custom thicknesses produced to order) |
| Hardness Range | Annealed: HRB 95 max (217 HBW max) |
| Surface Finishes | Bright Annealed, Passivated, Pickled, Electro-polished, PTFE/Xylan Coated |
| Certification | EN 10204 3.1 MTR, PMI Test Reports, Hardness & Proof Load Verification |
SS 317L Technical Properties & Chemical Composition
Chemical Composition of ASTM A240 UNS S31703 Washers (%)
| Element | SS 317L (UNS S31703 / 1.4438) |
|---|---|
| Carbon (C) | 0.035 max |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 1.00 max |
| Phosphorus (P) | 0.045 max |
| Sulfur (S) | 0.030 max |
| Chromium (Cr) | 18.00 – 20.00 |
| Molybdenum (Mo) | 3.00 – 4.00 |
| Nickel (Ni) | 11.00 – 15.00 |
| Iron (Fe) | 57.89 min (Balance) |
Mechanical Properties of UNS S31703 Washers
| Property / Parameter | Technical Value |
|---|---|
| Tensile Strength (MPa / psi) | 515 MPa / 75,000 psi min |
| Yield Strength 0.2% Offset (MPa / psi) | 205 MPa / 30,000 psi min |
| Elongation (% in 50mm) | 35% min |
| Density | 7.9 g/cm³ |
| Melting Point | 1400 °C (2550 °F) |
| Rockwell Hardness B (HR B) | 95 HRB max |
| Brinell Hardness (HBW) | 217 HBW max |
Equivalent Grades for SS 317L Washers
| Standard / System | Designation / Grade |
|---|---|
| UNS Designation | UNS S31703 |
| Werkstoff Nr. | 1.4438 |
| Euronorm Name | X2CrNiMo18-15-4 |
| JIS Standard | SUS 317L |
| ASTM Standard | ASTM A240 Grade 317L |
Comparison: SS 317L vs. SS 316L
| Performance Feature | SS 316L (UNS S31603) | SS 317L (UNS S31703) |
|---|---|---|
| Molybdenum Content | 2.00% – 3.00% | 3.00% – 4.00% |
| Pitting Resistance (PREN) | ~23 – 25 | ~29 – 31 |
| Sulfuric Acid Defense | Moderate in dilute solution | Strong resistance in medium concentrations |
| Crevice Attack Protection | Standard process defense | Enhanced protection in high-chloride solutions |
| Cost-Performance Ratio | Commercial baseline | Cost-effective bridge to super-austenitics |
Why Heavy Process Industries Specify SS 317L Washers
Superior Pitting Resistance: 3.0-4.0% molybdenum content resists aggressive localized crevice attack in chloride-dense environments.
Eliminates Weld-Zone Decay: Low-carbon (0.035% max) composition prevents intergranular carbide precipitation during joint welding.
Resists Severe Acid Attack: Performs reliably in hot sulfurous, acetic, citric, and dilute sulfuric acid processing streams.
Maintains High Tensile Preload: Yields 515 MPa tensile strength to maintain uniform clamping force under thermal stress.
Prevents Surface Galling: Precision cold-stamped bearing surfaces reduce thread binding during high-torque flange bolting.
Types of SS 317L 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 317L Plain Washers
SS 317L Spring Washers
SS 317L Lock Washers
SS 317L Square Washers
SS 317L Conical Washers
Key Technical Advantages
High Rupture and Tensile Strength
Yield strength of 205 MPa combined with 515 MPa minimum tensile capacity ensures reliable load retention under dynamic bolt preloads.
Creep Deflection Defense
Higher nickel (11.0% – 15.0%) and molybdenum levels prevent long-term stress relaxation in elevated-temperature fluid handling operations.
Dimensional Precision
Stamped to close engineering tolerances, ensuring flat bearing faces that eliminate galling and friction spikes during torque installation.
Surface Passivation Layer
Chemical passivation removes free iron contamination, forming a resilient chromium-molybdenum oxide passive film.
Cryogenic Ductility
Maintains toughness without brittle phase transformations in sub-zero processing applications.
Key Applications of SS 317L Washers
| Industry Sector | Primary Application | Operating Conditions |
|---|---|---|
| Pulp & Paper Processing | Bleaching tower flanges, digester vessel mountings | Exposure to chlorine dioxide, hypochlorites, and sulfur dioxide gases |
| Flue Gas Desulfurization (FGD) | Scrubber system bolting, ductwork anchors | Low pH acidic condensates containing chlorides and sulfates |
| Chemical Processing | Reactor vessel joints, acid heat exchangers | High-concentration organic acid streams at elevated process temperatures |
| Offshore Oil & Gas | Subsea manifolds, topside chemical injection skids | Splash-zone seawater exposure and acidic sour gas environments |
| Textile Dyeing Plants | Dye bath agitator mounts, acid vessel bolting | Hot acidic solutions mixed with dye chemicals and chloride salts |
Quality Testing & Inspection Standards
As a dedicated SS 317L Washers Supplier and SS 317L Washers Exporter, Aurum Overseas subjects every manufacturing lot to comprehensive quality verification before shipment.
- Positive Material Identification (PMI): Optical emission spectroscopy verifies exact molybdenum (3.0–4.0%) and nickel levels before manufacture.
- Dimensional Verification: Precision optical comparator testing ensures inner diameter, outer diameter, and parallel thickness conform to DIN 125 / ASME B18.21.1 limits.
- Hardness & Load Verification: Rockwell B (max 95 HRB) and Brinell hardness testing ensure compliance with ASTM A240 mechanical specifications.
- Full Certification Traceability: Every shipment is accompanied by EN 10204 3.1 Material Test Reports linking hardware directly to source heat numbers.
Global Export Markets
As a dedicated SS 317L Washers Exporter, Aurum Overseas supplies fully certified ASTM A240 UNS S31703 Washers to major industrial markets:
USA
Canada
Mexico
Germany
United Kingdom
France
Italy
Netherlands
Norway
UAE
Saudi Arabia
Qatar
Kuwait
Oman
Singapore
Malaysia
Australia
Frequently Asked Questions
SS 317L contains higher percentages of molybdenum (3.0% to 4.0%) and chromium (18.0% to 20.0%) compared to SS 316L (2.0% to 3.0% Mo). This enhanced chemistry provides superior resistance to pitting, crevice corrosion, and chemical acid attack in aggressive environments.
SS 317L washers perform efficiently from cryogenic temperatures up to approximately 800°C (1472°F) in non-scaling conditions, while offering creep resistance at elevated process temperatures.
Like other austenitic stainless steels, SS 317L is virtually non-magnetic in the fully solution-annealed state. Minor magnetic responses may occur following cold stamping, but these do not impact performance.
We supply metric and imperial sizes conforming to ASME B18.21.1, DIN 125, DIN 127, DIN 9021, ISO 7089, and ISO 7090, as well as custom drawings.
As an established SS 317L Washers Supplier, Aurum Overseas accepts inquiries directly via email. We provide competitive quotes, complete documentation, and global freight handling.
Contact Aurum Overseas
Aurum Overseas manufactures and stocks certified SS 317L Washers for immediate global dispatch.
Contact our technical sales team for instant pricing, material test reports, and custom size requirements.