Materials
Stainless Steel 303, 304, 309, 310, 316, 317, 321, 330, 347
303 Stainless Steel
Type: Austenitic stainless steel
Key Properties:
Excellent machinability, making it ideal for high-precision fasteners
Good corrosion resistance in mild environments
Moderate strength (lower than 304)
Fastener Applications:
Screws, nuts, bolts that require complex machining
Components where high-strength is not the primary requirement
304 Stainless Steel
Type: Austenitic stainless steel (most widely used)
Key Properties:
Excellent corrosion resistance in a wide range of environments
Good ductility and formability
Moderate strength
Fastener Applications:
General-purpose fasteners for industrial, food processing, chemical, and marine environments
Bolts, studs, nuts, and washers where corrosion resistance is key
309 Stainless Steel
Type: Austenitic stainless steel, high-temperature grade
Key Properties:
Excellent oxidation resistance at elevated temperatures
Moderate corrosion resistance in aggressive environments
Maintains strength at high temperatures (~870°C / 1600°F)
Fastener Applications:
Components exposed to high heat, such as furnace bolts, exhaust assemblies, or heat exchangers
310 Stainless Steel
Type: Austenitic stainless steel, heat-resistant
Key Properties:
Superior high-temperature strength and oxidation resistance compared to 309
Maintains mechanical integrity up to ~1100°C / 2000°F
Good corrosion resistance in oxidizing atmospheres
Fastener Applications:
Bolts and studs in high-temperature industrial or turbine applications
Heat exchanger and furnace components
316 Stainless Steel
Type: Austenitic stainless steel, molybdenum-bearing
Key Properties:
Excellent corrosion resistance, including chloride resistance
Good strength and ductility
Resistant to pitting and crevice corrosion in marine and chemical environments
Fastener Applications:
Fasteners for subsea, chemical, or marine applications
Bolts, studs, and screws requiring high corrosion resistance
317 Stainless Steel
Type: Austenitic stainless steel, higher alloyed than 316
Key Properties:
Slightly better corrosion resistance, especially to chlorides and acids
Good mechanical properties, similar to 316
Fastener Applications:
Critical chemical processing components
Bolts, nuts, and studs for more aggressive environments than 316
321 Stainless Steel
Type: Austenitic stainless steel, titanium-stabilized
Key Properties:
Excellent resistance to intergranular corrosion after welding or heat exposure
Maintains strength at elevated temperatures (up to ~870°C / 1600°F)
Fastener Applications:
Bolts and fasteners for high-temperature assemblies, especially welded structures
Aerospace, exhaust systems, and chemical processing
330 Stainless Steel
Type: Austenitic stainless steel, nickel-iron-chromium alloy
Key Properties:
Excellent oxidation and heat resistance up to ~1100°C / 2000°F
Good corrosion resistance in oxidizing environments
Retains mechanical properties at high temperatures
Fastener Applications:
Bolts and studs for furnaces, turbines, or heat exchangers
High-temperature industrial fasteners
347 Stainless Steel
Type: Austenitic stainless steel, niobium-stabilized
Key Properties:
Excellent resistance to intergranular corrosion, especially after welding
Good high-temperature strength (up to ~870°C / 1600°F)
Maintains corrosion resistance in oxidizing atmospheres
Fastener Applications:
Critical fasteners in aerospace, power generation, and chemical industries
Studs and bolts in welded high-temperature assemblies
Summary
303 → machinability focus, moderate corrosion resistance
304 / 316 / 317 → corrosion resistance focus, moderate strength
309 / 310 / 321 / 330 / 347 → high-temperature and welded assemblies, with varying corrosion resistance
In engineered fasteners, choosing among these stainless steels depends on:
Environment: corrosive, marine, chemical, or oxidizing
Temperature: ambient, high heat, or thermal cycling
Mechanical load: tensile and yield strength requirements
Fabrication needs: machining, forming, or welding
Materials
BRASS
BRONZE
COPPER
PH STAINLESS STEEL
DOING WHATEVER IT TAKES
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The manufacturing processes, testing capabilities, and quality systems featured throughout WN Global support the production of critical components and engineered fastening solutions across demanding industries. Connect with our team to learn how our manufacturing capabilities can support your project requirements.
