S-91247A515 7/8"-14 x 6 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional strength for demanding applications with Grade 5 classification and 120,000 psi tensile strength, ensuring reliable performance under high stress.
• Superior corrosion resistance provided by the zinc plating, extending the fastener's service life in harsh industrial environments.
• Precise and secure fastening due to the UNF fine thread and Class 2A thread fit, minimizing the risk of loosening in vibration-prone assemblies.
• Optimized for high-torque applications featuring an external hex drive and large 1 5/16" head width for easy installation with standard tools.
• Enhanced durability and wear resistance from Rockwell C25 hardness, maintaining structural integrity over repeated use.
• Versatile partial threading design allows for effective clamping on non-threaded sections, ideal for a range of assembly configurations.
• Compliance with major industry standards including ASME B18.2.1 and SAE J429, ensuring consistent quality and interchangeability.

Professional Applications & Engineering Value

This 7/8"-14 UNF hex head screw is engineered to address critical challenges in heavy machinery, structural steelwork, and industrial equipment assembly. The Grade 5 steel construction, combined with a zinc plated finish, provides robust resistance to environmental factors, reducing maintenance needs and downtime. The fine UNF threading and Class 2A thread fit ensure tight, secure connections that resist vibration-induced loosening, a common issue in dynamic applications. With a partially threaded shank, it offers precise clamping force control, making it suitable for assemblies requiring both threaded and unthreaded engagement. This fastener delivers reliable performance in construction, automotive, and manufacturing sectors, where high tensile strength and corrosion resistance are paramount for long-term operational safety and efficiency.

Specification Summary & Compliance

This hex head screw adheres to Class 2A thread fit tolerances per UNF standards, ensuring dimensional accuracy and compatibility. It meets ASME B18.2.1 and SAE J429 specifications for manufacturing consistency. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in regulated industries without hazardous substances.