Understanding Screw Property Classes: Taiyuanfeng Helps You Choose Right for Secure Connections

In the fastener industry, the property class of a screw directly determines its tensile strength, yield strength, and application scenario. Common classes include 4.8, 8.8, 10.9, and 12.9. Higher numbers indicate greater strength. For example, class 8.8 means a tensile strength of 800 MPa and a yield ratio of 0.8, while class 12.9 reaches over 1220 MPa, suitable for high-load conditions.

Correctly identifying the class marking is critical for international procurement. Taiyuanfeng strictly follows ISO and ASTM standards. All shipped screws are clearly marked with their property class stamp, and material test reports are provided, ensuring every batch is traceable and verifiable.

Different property classes require different processes: below class 8.8 mostly uses low-carbon steel cold heading; above class 10.9 requires alloy steel with heat treatment (quenching + tempering). Taiyuanfeng owns a full-process heat treatment line and a spectrometer, ensuring strict control from raw material to finished product, eliminating the risk of mixing or fake grades.

Whether you need conventional class 8.8 bolts or high-strength class 12.9 socket head cap screws, Taiyuanfeng offers one-stop supply for all property classes with various surface finishes (zinc plated, Dacromet, hot-dip galvanized). Please contact us for a catalog or technical data sheets for specific property classes.

If you have any questions about screw property classes or selection, Taiyuanfeng’s technical team is ready for free consultation. Let’s build safer connections with the right classes.