Looking for durable, strong fasteners that are corrosion-resistant? Stainless steel fasteners are a fantastic option in a wide variety of applications and different industries that perform under intense stress.
Stainless steel fasteners have tensile strengths from 700 MPa (Class 70) to over 1700 MPa (martensitic grades). This great strength and resistance to the elements make stainless steel fasteners excellent for construction and automotive applications.
In this tutorial, we’ll explore how strong stainless steel fasteners are, compare different grades to find the best fit, and how to make the right purchase for your needs.
Strength Characteristics of Stainless Steel Fasteners
Tensile Strength by Grade
The strength of stainless steel fasteners varies depending on grade and classification:
- ISO 3506 Class 70 (A2-70): Offers a minimum tensile strength of 700 MPa (101,500 psi) and is frequently used in general construction.
- ISO 3506 Class 80 (A4-80): Fabricated from 316 stainless steel, providing heightened corrosion resistance and a higher tensile strength of 800 MPa or more.
- Martensitic Stainless Steel (Grade 410): Can be heat-treated to achieve tensile strengths ranging from 1,241 to 1,724 MPa (180,000 to 250,000 psi), making it suitable for high-stress applications.
To view a detailed breakdown of stainless steel bolt tensile strength by grade, refer to our stainless steel bolt tensile strength chart. For further insights on the ISO fastener standards, continue reading.
Grade Comparisons: Austenitic, Martensitic, and Ferritic Stainless Steel
Austenitic Stainless Steel (304 and 316 Grades) :
- Tensile strength varies between 80,000 and 150,000 psi (550 and 1,034 MPa).
- Grade 316, featuring added molybdenum, provides superior corrosion resistance, rendering it optimal for marine environments.
Martensitic Stainless Steel (Grade 410) :
- It can attain tensile strengths of up to 1,724 MPa after undergoing heat treatment, making it exceptional for high-load applications.
Ferritic Stainless Steel:
- Exhibits lower tensile strengths, ranging from 448 to 600 MPa, and is suitable for low-stress operating conditions.
For comprehensive grade specifications, consult the stainless steel bolt grade chart. Read more on 304 vs. 316 stainless steel properties.
Corrosion Resistance vs. Strength
Ensuring an optimal balance between corrosion resistance and strength is essential when selecting stainless steel fasteners:
- Grade 304: Offers a balanced combination of strength and moderate corrosion resistance, suitable for diverse applications.
- Grade 316: Exhibits superior resistance to chloride corrosion, making it ideal for deployment within marine or chemical industries despite offering slightly lower tensile strength compared to martensitic grades.
For further insights into corrosion resistance by grade, and to explore a comparison of corrosion resistance and tensile strength, refer to the Fastener Grade Selection Guide.
Do Stainless Steel Bolts Easily Break?
Stainless steel bolts are engineered for endurance, although inappropriate usage can lead to problems:
- Work Hardening: Over time, the stainless steel can harden, subsequently bolstering its strength.
- Potential Breakages: Over-tightening or using fasteners in high-tensile applications beyond their grade rating can result in fractures.
For guidance on best practices for avoiding bolt failures, please refer to How to Prevent Bolt Failures.
Applications and Best Practices
Applications:
Stainless steel fasteners are extensively utilized in the following sectors:
- Construction: They provide structural resilience in challenging environments.
- Marine Industry: Stainless steel fasteners combat corrosion in saltwater conditions.
- Automotive: They offer durable support in vehicle assembly.
Best Practices:
- Implement anti-seize lubricants to mitigate galling during the assembly process.
- Select the appropriate grades based on environmental and mechanical specifications.
For further information on methods to prevent galling, refer to the galling prevention techniques. You can also learn more about marine-grade fasteners.
Conclusion
Stainless steel fasteners deliver tensile strengths ranging from 700 MPa (Class 70) to over 1,700 MPa (martensitic grades). Their unique amalgamation of strength, durability, and corrosion resistance renders them indispensable for industries such as construction, marine, and automotive. Selection of the appropriate grade guarantees long-term performance aligned with the specific exigencies of your project.
