S-91257A732 1/2"-13 x 5" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 psi tensile strength, ideal for high-stress structural connections.
• Superior corrosion resistance from zinc yellow-chromate plating, extending service life in harsh environments.
• Reliable fastening performance with Class 2A thread fit and UNC coarse spacing for quick assembly and vibration resistance.
• High durability backed by Rockwell C33 hardness and Grade 8 classification, reducing wear and replacement frequency.
• Easy installation and removal using standard external hex drive and 3/4" head width for common tool compatibility.
• Optimized thread engagement with partially threaded design, minimizing cross-threading risks in precise applications.
• Compliance with major industry standards including ASME B18.2.1 and SAE J429, ensuring consistent quality and safety.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, this Grade 8 hex head screw combines high-strength steel material with a zinc yellow-chromate finish to combat rust and chemical exposure in outdoor or humid conditions. The UNC coarse thread and Class 2A fit provide rapid installation and secure holding power in machinery, construction, and automotive assemblies, where vibration loosening is a concern. Its partially threaded shank allows for precise clamping without compromising joint integrity, making it a reliable choice for heavy-duty fastening in structural frames, equipment mounts, and load-bearing components that require consistent performance under stress.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit tolerances and UNC coarse spacing per ASME B18.2.1 and SAE J429 specifications. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance for environmental safety, with dimensions including a 1/2"-13 thread size, 5" length, and 3/4" head width in the inch system.