Thread Size-Guide for Automotive & Industrial Fasteners | Procure auto parts | custom fasteners

Understanding Fastener Thread Size

A fastener's thread size is defined by two key parameters:

1. Major Diameter: The largest diameter of the screw thread.

2. Thread Pitch (for Metric) or Threads Per Inch (TPI - for Imperial): Thread Pitch is the distance between successive threads (in mm). TPI is the number of threads within one inch.

These parameters dictate how a fastener engages with a corresponding nut or tapped hole.

Why Thread Size Matters for Performance and Compatibility

Selecting the correct thread size is non-negotiable for reliable fastening because it impacts:

• Compatibility: Ensures the bolt or screw can properly mate with a nut or tapped hole of the same size and pitch/TPI. Incorrect size or pitch leads to misalignment or inability to fasten.

• Strength: The thread profile and size significantly influence the bolt's tensile strength and shear strength. Choosing an undersized thread for a high-load application can lead to failure.

• Vibration Resistance: Fine threads (smaller pitch/higher TPI) often offer better resistance to loosening under vibration compared to coarse threads, due to a smaller helix angle and more threads engaged over a given length.

• Assembly Efficiency: Coarse threads generally allow for faster assembly due to fewer turns required for engagement and are less susceptible to cross-threading. Fine threads allow for finer adjustment of clamping force.

Our Comprehensive Range of Thread Sizes

At Zhejiang Zhongrui Auto Parts, we are equipped to provide a vast variety of metric and imperial thread sizes, essential for global automotive and industrial applications. Our range covers a broad spectrum, ensuring you can find the right fit for almost any requirement.

• Metric Thread Sizes:
  We offer a comprehensive range of metric thread sizes, from very small diameters used in electronics and intricate assemblies up to large diameters required for heavy-duty structural connections. Our capabilities include sizes like:

  • M1.6, M2, M2.5, M3, M3.5, M4, M4.5, M5, M6, M8, M10, M12, M14, M16, M20, M24, M30, M36, M42, M48, M50, M52, M64.
    This covers a wide spectrum of applications from small components to heavy machinery.

• Imperial (Inch) Thread Sizes:
  Serving markets that utilize imperial measurements, we also provide a wide selection of inch series thread sizes, including common coarse (UNC) and fine (UNF) threads:

  • From smaller sizes like #0-80, #000-120 up through larger diameters like 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 3/4", 7/8", 1", 1 1/8", 1 1/4", 1 3/8", 1 1/2", 1 3/4", 2".

  • Covering various TPI options for each diameter, including UNC and UNF series (e.g., 1/4"-20 UNC, 1/4"-28 UNF, 3/8"-16 UNC, 3/8"-24 UNF).

  • Including some less common TPIs like 1/4"-32, 5/16"-32, 3/8"-32.
    This extensive imperial range supports diverse manufacturing and repair needs.

Beyond the Size: Quality, Standards, and Expertise

Providing a wide range of thread sizes is just the beginning. At Zhejiang Zhongrui Auto Parts, our commitment to quality ensures that the fasteners we produce to these specifications are reliable and perform as expected. Our IATF16949 certified Quality Management System is integrated throughout our manufacturing process, from raw material selection and heat treatment to precision threading and rigorous inspection.

We manufacture fasteners compliant with various international standards (ISO, DIN, ASME/ANSI, JIS) and national standards (GB/T), ensuring that the thread sizes we produce conform to globally recognized specifications for dimensions and mechanical properties. This multi-standard capability and focus on quality are crucial for providing dependable components for the automotive and industrial sectors.

Finding the Right Thread for Your Application

Selecting the perfect thread size involves more than just matching a hole; it requires considering the application's load requirements, vibration levels, environmental exposure, and assembly process. Our team of experts is equipped to provide guidance on choosing the optimal thread size, material, and finish for your specific needs, leveraging our deep understanding of fastener standards and automotive/industrial applications.

Contact us to find out more about our capabilities and how we can meet your specific fastener needs.

Meet a few members of our dedicated team, ready to help you:
Coco Chen, Director of Business Development: coco.chen@zjzrap.com
Freddie Xiao, Account Manager: freddie.xiao@zjzrap.com
Brian Xu, Technical Sales Assistant: brian.xu@zjzrap.com

Explore our capabilities and comprehensive product range: https://www.zjzrqc.com/product

IATF16949 Certified

HQ& Factory Address:
No. 680, Ya'ao Road, Daqiao Town, Nanhu District, Jiaxing City, Zhejiang Province, China


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