S-91247A116 5/16"-24 x 2 1/4" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With 120,000 psi tensile strength, this screw provides reliable load-bearing capacity for demanding applications, reducing the risk of fastener failure.
• Superior Corrosion Protection – Zinc plating offers enhanced resistance to rust and environmental elements, extending service life in industrial settings.
• Precision Fine Threading – 5/16"-24 UNF fine threads ensure tighter, more secure fastening with improved vibration resistance compared to coarse threads.
• High Hardness & Durability – Rockwell C25 hardness provides excellent wear resistance and maintains thread integrity under repeated use.
• Easy Installation & Removal – External hex drive and standard hex head design allow for quick, tool-friendly assembly and disassembly with common wrenches.
• Consistent Thread Fit – Class 2A thread fit guarantees dimensional accuracy and smooth engagement with mating nuts or tapped holes.
• Partial Threading Versatility – Partially threaded shank enables precise clamping force control, ideal for applications requiring specific grip lengths.

Professional Applications & Engineering Value

This Grade 5 hex head screw is engineered to address critical challenges in heavy machinery, automotive assemblies, and structural frameworks where vibration loosening and material fatigue are common. The UNF fine threading provides superior holding power in high-stress environments, while the zinc plated finish combats corrosion in outdoor or humid conditions. Its partially threaded design allows for optimal load distribution, preventing joint slippage in dynamic applications. Manufactured from high-strength steel and compliant with ASME B18.2.1 and SAE J429 standards, it ensures interchangeability and reliability across industrial fastening systems, reducing maintenance downtime and enhancing operational safety.

Specification Summary & Compliance

This screw adheres to Class 2A thread tolerance for precise fit, with UNF fine thread specifications (5/16"-24). It meets ASME B18.2.1 and SAE J429 manufacturing standards for dimensional consistency and performance. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions are fully addressed.