How to Choose the Right Flange Nut for Your Application

Flange nuts are widely used in automotive, machinery, and structural applications thanks to their integrated washer-like base, which distributes pressure more evenly. However, choosing the right flange nut isn’t as simple as it may seem. From material and thread size to locking features and corrosion resistance, several factors need to be considered to ensure optimal performance and safety.

Choose Flange Nut Material Based on Application Needs

How to choose a flange nut begins with selecting the right material. The working environment and mechanical load will largely determine your choice:

• Carbon steel flange nuts are economical and suitable for general-purpose fastening.
• Stainless steel 304 flange nuts offer better corrosion resistance, ideal for humid or mildly corrosive environments.
• Stainless steel 316 flange nuts are preferred for marine or chemical exposure due to their superior resistance to salt and harsh chemicals.

At Xinchi Fasteners, we provide a full range of flange nuts made from high-quality carbon steel, 304 stainless steel, and 316 stainless steel. All materials are strictly inspected to meet international standards.

Match Flange Nut Thread Size and Tolerance

Thread compatibility is critical when choosing a flange nut. Be sure to:

• Match the thread pitch and diameter with the corresponding bolt (e.g., M8 x 1.25).
• Pay attention to the tolerance grade (commonly 6H for nuts), which affects how tight or loose the fit will be.

Xinchi supports a wide variety of thread sizes and tolerance grades, with precise machining backed by over 102 cold heading machines and advanced testing equipment.

Consider the Flange Dimensions and Shape

Not all flange nuts have the same flange size:

• A larger flange diameter distributes more pressure and is suitable for softer materials like aluminum or plastic.
• For limited space or recess-mounted applications, a smaller or serrated flange may be more appropriate.

Our engineers at Xinchi Fasteners can help customers select or even customize the flange shape and size to fit specific installation scenarios.

Locking Requirements: Should You Choose a Serrated Flange Nut?

If your application requires vibration resistance—such as in automotive or heavy machinery—serrated flange nuts are a strong choice.

• The serrations bite into the material surface, preventing loosening under vibration.
• However, they cannot be used with washers and may damage delicate surfaces.

Xinchi offers both smooth flange nuts and serrated flange lock nuts, including special anti-loosening designs suitable for automation assembly and heavy-duty applications.

Flange Nut Corrosion Resistance: Do You Need Stainless Steel?

Environments with moisture, chemicals, or outdoor exposure demand better corrosion resistance. Here’s a quick guideline:

• Mild exposure → Stainless Steel 304 or Zinc-plated carbon steel
• Severe exposure (marine/chemical) → Stainless Steel 316
• Dry indoor use → Carbon steel flange nuts may suffice

All Xinchi fasteners undergo surface treatment options, including zinc plating, black oxide, and passivation to meet the specific corrosion protection level your project needs.

Proper Bolt Matching and Installation Tips

Flange nuts should be paired with compatible bolts in both size and material:

• Always use matching thread standards (metric vs. imperial).
• For structural applications, ensure both bolt and nut meet the required grade and tensile strength (e.g., Grade 8.8 or 10.9).
• Torque to the correct specification to avoid overtightening or stripping threads.

Xinchi also supplies matched hex bolts and flange bolts with customized packaging and labeling, making it easier for clients to streamline sourcing.

Why Choose Xinchi Fasteners

With over 18 years of experience in fastener manufacturing, Xinchi Fasteners offers unmatched advantages:

• Factory Scale: Two six-story production buildings covering 30,000 m², with advanced automation and strict quality control.
• High Capacity: Over 102 cold heading machines, with a daily output exceeding 10 million pieces.
• Customization: OEM/ODM services, fast mold development, and tailored packaging solutions.
• Global Compliance: Our products meet the RoHS, REACH, ISO, and SGS standards.

XINCHI is a trustworthy fastener company, especially in furniture nuts. We have a factory,  founded in 2007. We are the designated fastener supplier to“STAPLE”. As a trusted fastener supplier, XINCHI offers a wide range of high-quality fasteners, including nuts, screws, bolts, rivets, and washers.

Let us know what you’re working on—we’ll help you choose the best fastening solution for your needs.