254 SMO Fasteners Supplier
MT.BOLTS manufactures 254 SMO fasteners using high-alloy austenitic stainless steel known for exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking—especially in chloride-rich environments. These fasteners are engineered for demanding applications in seawater systems, chemical processing, pulp and paper bleaching, and offshore equipment.
Our 254 SMO fasteners have the following specifications:
- Diameter: M3 to M64 | #4 to 2.5″
- Length: 6 mm to 500 mm | 0.25″ to 20″
- Thread Pitch: Metric (Coarse/Fine) | UNC/UNF
- Standards: ASME B18.2.1, ASME B18.3, ASME B18.2.2, DIN/ISO/EN (e.g., DIN 933, DIN 934)
- Material Specifications: ASTM A479 (254 SMO), ASTM A182 F44
- Types: Bolts, Screws, Nuts, Washers, Studs
We regularly supply stainless steel fasteners and bolts made from 254 SMO. For your procurement reference, its chemical composition and physical properties are provided below.
| Alloy Grade | UNS Number | Characteristics |
| 254 SMO | S31254 | Exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride-rich and seawater environments; high strength and excellent performance in acidic and high-temperature applications |
254 SMO Fasteners Chemical Composition
| Element | Content (% by weight) |
| Carbon (C) | ≤ 0.020 |
| Manganese (Mn) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.010 |
| Silicon (Si) | ≤ 0.80 |
| Chromium (Cr) | 19.5 – 20.5 |
| Nickel (Ni) | 17.5 – 18.5 |
| Molybdenum (Mo) | 6.0 – 6.5 |
| Nitrogen (N) | 0.18 – 0.22 |
| Iron (Fe) | Balance |
254 SMO Fasteners Mechanical Properties
| Property | Value | Unit |
| Tensile Strength (min) | 650 | MPa |
| Yield Strength (0.2% offset, min) | 300 | MPa |
| Elongation (min) | 35 | % |
| Hardness (max) | 100 | HRB |
| Density | 8 | g/cm³ |
254 SMO Fasteners Types
MT.BOLTS offers a comprehensive range of 254 SMO Fasteners for your selection to meet various application requirements:
254 SMO Hex Head Screw Bolts
254 SMO Square Head Bolts
254 SMO Flange Bolts
254 SMO Serrated Flange Bolts
254 SMO Eye bolts
254 SMO Carriage Bolts
254 SMO Elevator Bolts
254 SMO U-Bolts
254 SMO Anchor Bolts
254 SMO Expansion Bolt
254 SMO Lag Bolts
254 SMO U-Bolts
254 SMO Hex Head Lag Screws
254 SMO Shoulder Screws
254 SMO Socket Cap Screws
254 SMO Self-Tapping Screws
254 SMO Hex Nuts
254 SMO Serrated Flange Nuts
254 SMO Lock Nuts
254 SMO Wing Nuts
254 SMO Coupling Nut
254 SMO Square Nuts
254 SMO Acorn Nuts
254 SMO Wing Nuts
254 SMO Fully Threaded Rods & Studs
254 SMO Equal Thread Length Rods & Studs
254 SMO Unequal Thread Length Rods & Studs
254 SMO Single End Threaded Studs
254 SMO Weld Studs
254 SMO Press-In Captive Studs
254 SMO Flat Washers
254 SMO Lock Washers
254 SMO Curved Washers
254 SMO Wave Washers
254 SMO Square Washers
254 SMO Belleville Washers
Why Choose MT.BOLTS
- Material Diversity
- Standardized Production
- Ample Inventory
- Competitive Pricing
- Low-MOQ Customization
Reasons to Choose 254 SMO Fasteners
Excellent Corrosion Resistance
Highly resistant to pitting, crevice corrosion, and stress corrosion cracking in chloride-rich environments.
High PREN Value (~42–45)
PREN (Pitting Resistance Equivalent Number) ensures outstanding performance in seawater and aggressive chemical environments.
Superior Strength Compared to 316L
Offers almost double the strength of 316L stainless steel while maintaining excellent ductility and toughness.
Resistance to Acids
Withstands organic acids (e.g., acetic, formic) and inorganic acids (e.g., sulfuric, phosphoric) under harsh conditions.
High Temperature Tolerance
Performs well in elevated temperature applications without compromising strength or corrosion resistance.
Low Maintenance Cost
Long service life reduces downtime and replacement frequency, ideal for critical and remote installations.
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Application of 254 SMO Fasteners
- Marine Environments
Ideal for seawater piping, offshore platforms, heat exchangers, and ballast systems. - Chemical Processing Plants
Used in reactors, tanks, pumps, and piping exposed to harsh acids and chlorides. - Desalination Plants
Fasteners used in brine systems, evaporators, and reverse osmosis units. - Pulp and Paper Industry
Employed in bleach plants, digesters, and storage tanks handling aggressive media. - Power Generation
For scrubbers, cooling water systems, and flue gas desulfurization units. - Food & Pharmaceutical Equipment
Where hygiene and corrosion resistance are critical under cleaning chemical exposure.
FAQ About 254 SMO Fasteners and Bolts
254 SMO is a high-alloy austenitic stainless steel (UNS S31254) with high levels of chromium, molybdenum, and nitrogen, providing superior resistance to pitting, crevice corrosion, and chloride-induced stress corrosion cracking.
They are widely used in seawater handling systems, chemical processing, desalination plants, pulp and paper industries, and offshore oil & gas platforms.
- Outstanding corrosion resistance in aggressive chloride environments
- High mechanical strength
- Excellent weldability and formability
- Long service life even in extreme applications
They can be used alongside other high-alloy or super austenitic stainless steels, but galvanic corrosion should be considered when paired with lower-grade materials.
They are commonly manufactured to standards such as ASTM A479, ASTM A276, and fastener standards like ASME B18.2.1, DIN 933, and ISO 4017.
Common types include bolts, nuts, washers, screws, studs, and custom machined components.
Yes. 254 SMO has excellent resistance to seawater corrosion, especially pitting and crevice corrosion, making it ideal for marine and offshore environments.
While Duplex grades like UNS S31803 offer a balance of strength and corrosion resistance, 254 SMO generally provides better corrosion resistance but slightly lower mechanical strength.
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