S-91257A847 3/4"-10 x 3" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with Grade 8 classification, providing 150,000 psi tensile strength and Rockwell C33 hardness for reliable performance in high-stress applications.
• Superior corrosion resistance due to zinc yellow-chromate plating, extending service life in harsh industrial environments and reducing maintenance needs.
• Optimal clamping force and vibration resistance from the partially threaded design and coarse UNC thread, ensuring secure fastening and minimizing loosening over time.
• Easy installation and removal with an external hex drive and standard 1 1/8" head width, allowing for efficient use with common tools and reducing assembly time.
• Precise thread fit and compatibility with Class 2A thread standards, ensuring smooth engagement and reliable connections in various machinery and equipment.
• Compliance with industry standards including ASME B18.2.1 and SAE J429, guaranteeing consistent quality and safety for industrial and automotive applications.
• Environmental and regulatory safety through RoHS 3 and REACH compliance, supporting sustainable and safe manufacturing practices.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial settings, such as structural assemblies, machinery, and automotive systems where high tensile strength and corrosion resistance are paramount. The steel material combined with zinc yellow-chromate plating provides robust protection against rust and wear, reducing downtime and replacement costs. Featuring a 3/4"-10 UNC coarse thread and partially threaded design, it ensures effective load distribution and clamping force, preventing joint failure under dynamic loads. Ideal for applications requiring external hex drive convenience and right-hand thread standardization, this fastener delivers reliable performance in construction, manufacturing, and equipment maintenance, enhancing operational efficiency and longevity.

Specification Summary & Compliance

This hex head screw adheres to precise dimensional standards, including a Class 2A thread fit for consistent accuracy and a 3/4"-10 UNC coarse thread with a minimum thread length of 1 3/4". It meets ASME B18.2.1 and SAE J429 specifications for manufacturing quality, ensuring reliable performance in demanding environments. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental safety and regulatory requirements in industrial applications.