S-91236A570 1/4"-20 x 8" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 60,000 psi ensures reliable performance under heavy loads, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the zinc plating protects the screw from rust and environmental degradation, extending service life in harsh conditions.
• Coarse UNC threading provides faster installation and better resistance to vibration loosening compared to fine threads, ideal for quick assembly.
• Class 2A thread fit offers excellent interchangeability and ease of assembly, minimizing production delays and ensuring consistent performance.
• Partial threading design allows for precise clamping force control, making it perfect for applications where specific unthreaded grip length is required.
• External hex drive and hex head enable high-torque installation with common tools, facilitating efficient maintenance and assembly.
• Compliance with major industry standards including ASME B18.2.1 and ASTM A307 guarantees material quality and dimensional accuracy for dependable engineering use.

Professional Applications & Engineering Value

This 1/4"-20 x 8" steel hex head screw is engineered to address critical fastening challenges in heavy-duty industrial applications, such as machinery assembly, structural frameworks, and construction projects. The zinc plating provides a durable barrier against corrosion, significantly reducing maintenance needs in environments exposed to moisture or chemicals. With its UNC coarse thread and Class 2A thread fit, it ensures quick, secure installation and reliable performance under vibration, preventing loosening over time. The partially threaded shank allows for optimal grip on materials, making it ideal for scenarios where precise clamping is essential. Manufactured from ASTM A307 steel and compliant with ASME B18.2.1, this screw delivers consistent strength and durability, supporting long-term operational safety and efficiency in demanding sectors like manufacturing, automotive, and infrastructure.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 2A thread fit for standard dimensional accuracy and ease of assembly. It is manufactured in accordance with ASME B18.2.1 and ASTM A307 specifications, ensuring reliable mechanical properties and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in various industrial environments without hazardous substances.