S-91247A368 1/2"-20 x 5" 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 damage, extending service life in industrial and outdoor settings.
• Fine UNF threading (1/2"-20) provides enhanced grip and vibration resistance, maintaining secure connections in machinery and equipment.
• Grade 5 strength classification and Rockwell C25 hardness offer a robust balance of durability and toughness for heavy-duty mechanical assemblies.
• Partially threaded design allows for precise clamping force control, ideal for applications where unthreaded shank sections are needed for structural integrity.
• Class 2A thread fit ensures consistent, easy assembly with standard nuts and tapped holes, improving installation efficiency and reducing production downtime.
• External hex drive and hex head enable quick, secure tightening with common tools, facilitating maintenance and reducing labor time.

Professional Applications & Engineering Value

This Grade 5 hex head screw is engineered to address critical challenges in industrial fastening, such as vibration loosening and corrosion-induced degradation. Constructed from high-strength steel and featuring a zinc-plated finish, it delivers long-lasting performance in harsh environments, including construction machinery, automotive assemblies, and heavy equipment. The 1/2"-20 UNF fine thread enhances load distribution and resistance to dynamic stresses, while the partially threaded configuration provides optimal clamping in bolted joints. By meeting ASME B18.2.1 specifications, it ensures dimensional accuracy and compatibility, reducing the risk of mismatches and improving overall system reliability for B2B procurement needs.

Specification Summary & Compliance

This screw adheres to precise inch system dimensions, including a Class 2A thread fit for consistent tolerance and a 5" length with a minimum thread length of 1 1/4". It conforms to ASME B18.2.1 and SAE J429 standards for mechanical properties and design. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring environmental safety and regulatory adherence in global industrial markets.