S-91247A457 5/8"-18 x 8" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance with zinc plating protects against rust and environmental degradation, extending service life in harsh industrial environments.
• Precision Class 2A thread fit guarantees smooth assembly and secure fastening, minimizing cross-threading and installation errors.
• Grade 5 steel construction with Rockwell C25 hardness provides excellent durability and resistance to wear, maintaining integrity through repeated use.
• Partially threaded design allows for optimal clamping force distribution, ideal for applications requiring precise joint security.
• External hex drive and hex head facilitate easy installation and removal with standard tools, improving maintenance efficiency.
• Compliance with ASME B18.2.1 and SAE J429 standards ensures consistent quality and interoperability in regulated industrial settings.

Professional Applications & Engineering Value

This Grade 5 steel hex head screw is engineered to address critical challenges in heavy-duty industrial applications, such as machinery assembly, structural frameworks, and automotive systems. The 5/8"-18 UNF fine threading and Class 2A thread fit provide superior vibration resistance and precise alignment, reducing loosening in dynamic environments. Made from high-strength steel with a zinc plated finish, it combats corrosion in outdoor or humid conditions, ensuring long-term reliability. The partially threaded configuration concentrates clamping force where needed, preventing joint slippage and enhancing safety. Ideal for sectors requiring robust high-strength fastening solutions, this fastener delivers consistent performance under tensile and shear loads, supported by its compliance with industry standards like ASME and SAE.

Specification Summary & Compliance

This fastener features a 5/8"-18 UNF fine thread with Class 2A fit for precise dimensional accuracy, ensuring compatibility with standard nuts and components. It adheres to ASME B18.2.1 and SAE J429 Grade 5 specifications, guaranteeing consistent manufacturing quality. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for hazardous substances.