201 and 304 stainless steel bolts are the two most widely used stainless fasteners for fastener procurement and engineering selection.
Many purchasers confuse these two products because they look nearly identical from appearance. However, they have huge gaps in corrosion resistance, chemical composition, service life, toughness and applicable environments. Choosing the wrong material will easily lead to equipment rusting, bolt fracture and even project rework.
Therefore, Handan Jihao Fasteners will walk you through the actual differences between 201 and 304 stainless steel bolts.
1. Core Differences in Chemical Composition
The anti-rust performance of stainless steel is entirely determined by its chromium and nickel content.
201 Stainless Steel Bolts
- Chromium content: 16%–18%
- Extremely low nickel content: only 1%–2%
- Manganese is used to replace nickel to cut raw material costs
- Belongs to economical low-grade stainless steel
- Unstable metallographic structure with weak corrosion resistance
304 Stainless Steel Bolts
- Standard 18-8 stainless steel in the industry
- Chromium content: 18%–20%
- Nickel content: 8%–10%
- Balanced chromium-nickel ratio with stable internal structure
- Standard material for general industrial, food-grade and outdoor applications
Summary: The massive difference in nickel content is the fundamental reason why 201 rusts easily while 304 delivers stable anti-corrosion performance.
2. Comparison of Anti-Rust & Corrosion Resistance
201 Stainless Steel Bolts
- Poor overall corrosion resistance
- Cannot withstand humid air, rainwater, salt mist and fog
- Prone to rust when used in coastal areas, outdoors or humid workshops
- Thin passive film on the surface that gets damaged by oxidation easily
- Not resistant to weak acid and weak alkali industrial environments
304 Stainless Steel Bolts
- Excellent comprehensive anti-rust performance
- Resists rain, humidity, atmospheric oxidation and mild acid & alkali corrosion
- Suitable for long-term exposed outdoor installation
- Great salt spray resistance, ideal for coastal, municipal and photovoltaic projects
3. Mechanical Properties: Hardness, Toughness & Crack Resistance
201 Stainless Steel
- High hardness but brittle texture
- Poor ductility and insufficient toughness
- Prone to cracking during bending, stamping and welding
- Likely to suffer fatigue fracture under long-term vibration
304 Stainless Steel
- Moderate hardness with outstanding toughness
- Resistant to cracking and thread galling
- Excellent welding performance
- Vibration and fatigue resistant, fit for long-running equipment
Simple summary: 201 is hard yet brittle; 304 features balanced hardness and reliable toughness.
Frequently Asked Questions (FAQ)
Q1: Application Scenarios for 201 Stainless Steel Bolts
- Interior decoration and furniture fixing
- Indoor brackets and non-load-bearing fixation of ordinary equipment
Q2: Application Scenarios for 304 Stainless Steel Bolts
- Outdoor steel structures, guardrails, curtain walls and street light projects
- Photovoltaic supports, wind power accessories and outdoor mechanical equipment
We supply bulk stainless steel bolts, nuts, washers, threaded rods and non-standard custom fasteners in all sizes of grade 201 and 304. All products are manufactured in strict accordance with DIN, ISO and national standards with genuine raw materials and stable salt spray resistance test performance. Material certificates and factory inspection reports are available upon request.
Please contact us via WhatsApp: +8613111607537 to get detailed prices.