Table of Contents
- SMO 254 (6MO) Washers Overview
- SMO 254 Washers Specifications
- SMO 254 Technical Properties & Composition
- SMO 254 vs. 316L Stainless Steel
- Why Industries Prefer SMO 254 Washers
- Types of SMO 254 Washers
- Key Technical Advantages
- Key Applications of SMO 254 Washers
- Quality Testing & Inspection
- Global Export Markets
- Frequently Asked Questions
- Contact Aurum Overseas
SMO 254 (6MO) Washers Suppliers & Exporters
Aurum Overseas is a premier SMO 254 Washers Supplier and SMO 254 Washers Exporter, stocking high-performance super austenitic fasteners in Plain, Spring, Lock, Square, and Conical styles built to ASME B18.21.1, DIN 125, and ISO 7089 standards.
-washers.webp "SMO 254 / 6Mo Washers")
Alloyed with 6.00–6.50% molybdenum, nitrogen, and copper, these UNS S31254 Washers deliver maximum resistance to pitting, crevice corrosion, and stress corrosion cracking. As a global SMO 254 Washers Exporter, we supply fully certified 6Mo Stainless Steel Washers and 6Mo Alloy Washers with 100% mill traceability for rapid worldwide dispatch.
SMO 254 Washers Specifications
| Parameter | Technical Specification / Standard Range |
|---|---|
| Material Grade | SMO 254 / 6Mo / 6% Moly |
| UNS Designation | UNS S31254 Washers |
| Werkstoff Number | 1.4547 (X1CrNiMoCuN20-18-7) |
| Manufacturing Standards | ASTM B688, ASTM A240 / ASME SA240, ASTM F467 |
| Dimensional Specifications | ASME B18.21.1, DIN 125 A/B, DIN 127 B, DIN 9021, ISO 7089, ISO 7090 |
| Washer Types | Plain Washers, Spring Washers, Lock Washers, Square Washers, Conical 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) |
| Delivery Condition | Solution Annealed (1150°C to 1200°C, rapid water quench) |
| Hardness Limit | ≤ 223 HB / ≤ 96 HRB |
| Surface Finishes | Bright Machined, Passivated, Pickled, Descaled |
| Certification | EN 10204 3.1 MTR, PMI Verification, Pitting Resistance Testing |
SMO 254 Technical Properties & Composition
Chemical Composition of UNS S31254 Washers (%)
| Element | Specification Range (%) |
|---|---|
| Chromium (Cr) | 19.50 – 20.50 |
| Nickel (Ni) | 17.50 – 18.50 |
| Molybdenum (Mo) | 6.00 – 6.50 |
| Copper (Cu) | 0.50 – 1.00 |
| Nitrogen (N) | 0.18 – 0.22 |
| Carbon (C) | ≤ 0.020 |
| Iron (Fe) | Balance |
Mechanical Properties of UNS S31254 Washers
| Mechanical Parameter | Specified Minimum Value |
|---|---|
| Tensile Strength (MPa) min | ≥ 650 |
| Yield Strength 0.2% Proof (MPa) min | ≥ 300 |
| Elongation (% in 50mm) min | ≥ 35 |
| Brinell Hardness (HBW) max | ≤ 223 |
| Rockwell B Hardness (HRB) max | ≤ 96 |
Equivalent Grades of SMO 254 Washers
| Standard / System | Equivalent Designation |
|---|---|
| UNS Designation | UNS S31254 |
| Werkstoff Nr. | 1.4547 |
| EN Standard | X1CrNiMoCuN20-18-7 |
SMO 254 vs. 316L Stainless Steel
| Property / Feature | SMO 254 (UNS S31254) | SS 316L (UNS S31603) |
|---|---|---|
| Molybdenum Content | 6.00 – 6.50% | 2.00 – 3.00% |
| Pitting Resistance Equivalent (PREN) | ≥ 42 (High PREN super austenitic) | ~23–25 (Standard austenitic) |
| Proof Yield Strength | ≥ 300 MPa (Nitrogen strengthened) | ~220 MPa |
| Resistance to Crevice Attack | Exceptional in warm, stagnant seawater | Susceptible to localized pitting in halides |
| Acid Service Performance | Superior in halide-bearing acidic media | Limited to low-concentration mild acids |
| Cost-Performance Ratio | Cost-effective alternative to high-nickel alloys | Standard economy grade for mild environments |
Why Industries Prefer SMO 254 Washers
High PREN Value (≥ 42): 6.00–6.50% molybdenum and nitrogen prevent severe pitting and localized wall degradation.
Stagnant Chloride Defense: Resists crevice attack under bolt heads in static saltwater and marine environments.
300 MPa Yield Strength: Nitrogen strengthening doubles the load-bearing capacity of standard 300-series stainless hardware.
Acid Processing Stability: Superior performance in dilute sulfuric, hydrofluoric, and phosphoric acid environments where 316L fails.
Chloride SCC Resistance: Prevents stress corrosion cracking under high mechanical tension and elevated process temperatures.
Types of SMO 254 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.
SMO 254 Plain Washers
SMO 254 Spring Washers
SMO 254 Lock Washers
SMO 254 Square Washers
SMO 254 Conical Washers
Key Technical Advantages
Self-Healing Passive Film
High chromium-molybdenum content rapidly rebuilds the protective oxide layer upon surface abrasion.
Non-Magnetic Core
Stable austenitic matrix maintains near-zero magnetic permeability in precision equipment.
Anti-Galling Performance
Low surface friction prevents thread binding and seizing during high-torque tightening.
Low-Carbon Intergranular Protection
Carbon level below 0.020% eliminates carbide precipitation and maintains grain-boundary strength.
Thermal Expansion Matched
Expands uniformly with standard stainless steel bolting to maintain constant joint compression during thermal cycling.
Key Applications of SMO 254 Washers
| Industry Sector | Application | Operating Environment |
|---|---|---|
| Desalination Plants | High-pressure reverse osmosis pump flanges and manifold piping | High-velocity seawater, hyper-saline brine, and high pressure |
| Offshore Oil & Gas | Subsea riser clamps, topside heat exchangers, and deck bolting | Harsh marine salt spray, splash zone exposure, and sour hydrocarbons |
| Pulp & Paper Bleaching | Chlorite and chlorine dioxide bleaching tower equipment | High concentration of active bleach compounds and hot acidic fluids |
| Flue Gas Desulfurization (FGD) | Scrubber vessel interior supports and ductwork flange connections | Corrosive acid condensates containing chloride-rich slurry |
| Chemical Processing | Phosphoric and organic acid reactor vessels and piping | Highly acidic media with active halide contaminants |
Quality Testing & Inspection
As a leading SMO 254 Washers Supplier, Aurum Overseas enforces strict quality protocols across production batches:
- Chemical Analysis: Positive Material Identification (PMI) testing confirming 15.00–17.50% Cr, 3.00–5.00% Ni, and 3.00–5.00% Cu alloy composition before dispatch.
- Mechanical & Hardness Testing: Load and hardness verification confirming high-strength performance with tensile strength ≥1310 MPa and yield strength ≥1170 MPa.
- Dimensional Inspection: Precision optical and micrometer checks verifying washer flatness, inner diameter, outer diameter, and thickness tolerances.
- Traceable Documentation: Complete material test certificates providing full heat traceability from raw mill material to final shipment.
Global Export Markets
As an established SMO 254 Washers Exporter, Aurum Overseas supplies fully certified UNS S31254 Washers to global energy and chemical hubs:
USA
Canada
Mexico
Germany
United
Kingdom
France
Italy
Netherlands
Norway
UAE
Saudi
Arabia
Qatar
Kuwait
Oman
Singapore
Malaysia
Australia
Frequently Asked Questions
SMO 254 contains 6.00–6.50% Molybdenum, providing a PREN ≥ 42, which resists pitting and crevice attack in high-chloride environments where 316L rapidly degrades.
While 6Mo Stainless Steel Washers offer high temperature strength, prolonged exposure above 400°C is generally avoided to prevent precipitation of brittle intermetallic phases.
UNS S31254 Washers feature a minimum yield strength of 300 MPa, strengthened through nitrogen alloy additions.
Yes, their high noble potential minimizes galvanic corrosion when paired with higher-grade alloys in marine or chemical process piping.
As an experienced SMO 254 Washers Exporter, we supply full EN 10204 3.1 Material Test Reports (MTR) covering heat numbers, mechanical values, and chemical composition.
Contact Aurum Overseas
Aurum Overseas manufactures and stocks SMO 254 (6MO) Washers for urgent global project requirements.
Contact our technical sales division for immediate pricing, mill certifications, and lead times.