S-91247A146 5/16"-24 x 7 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Enhanced Durability: Zinc plating provides superior corrosion resistance, extending service life in harsh industrial environments.
• High Tensile Strength: 120,000 psi tensile strength ensures reliable performance under heavy loads and vibration.
• Precise Thread Engagement: Class 2A thread fit and 5/16"-24 UNF fine threads offer excellent vibration resistance and secure fastening.
• Optimized Load Distribution: Partially threaded design concentrates strength where needed, reducing stress on the shank.
• Easy Installation & Removal: External hex drive and standard 1/2" head width allow for quick, tool-friendly assembly and disassembly.
• Consistent Hardness: Rockwell C25 hardness ensures dimensional stability and resistance to wear during repeated use.
• Broad Material Compatibility: Steel construction with zinc finish is suitable for fastening a wide range of materials in demanding applications.

Professional Applications & Engineering Value

This Grade 5 hex head screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, structural frameworks, and equipment manufacturing. The partially threaded configuration minimizes thread damage and distributes clamping force effectively, preventing joint failure under dynamic loads. With 5/16"-24 UNF fine threads, it delivers superior vibration resistance compared to coarse threads, making it ideal for applications subject to constant motion or shock. The zinc plating adds a protective barrier against moisture and chemicals, reducing maintenance needs in corrosive environments. Combined with a 120,000 psi tensile strength and external hex drive for easy torque application, this fastener ensures long-term reliability in construction, automotive, and industrial maintenance projects where precision and durability are paramount.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit tolerances for consistent engagement and meets ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and performance reliability. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing the absence of hazardous substances. The UNF fine threading and partial threading design follow standardized manufacturing practices, providing assurance of quality and suitability for regulated industrial applications.