S-91286A159 5/16"-18 x 1 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the zinc-flake coating extends service life in harsh industrial environments, minimizing maintenance needs.
• High hardness (Rockwell C33) provides excellent wear resistance, maintaining thread integrity and drive engagement over repeated use.
• Coarse UNC threading with Class 2A fit allows for quick assembly and secure fastening, even in materials prone to vibration or thermal expansion.
• Partially threaded design offers optimal clamp force distribution, ideal for joints requiring precise load-bearing capabilities.
• External hex drive and standard head dimensions ensure compatibility with common tools, streamlining installation and reducing labor time.
• Compliance with ASME, RoHS 3, and REACH standards guarantees product quality, safety, and environmental responsibility for global supply chains.

Professional Applications & Engineering Value

Engineered for demanding environments, this Grade 8 hex head screw combines high tensile strength and zinc-flake coating to address common industrial challenges like vibration loosening and corrosion. The 5/16"-18 UNC coarse thread and Class 2A fit ensure rapid, secure fastening in heavy machinery, structural steel connections, and automotive assemblies, where reliability is critical. Its partially threaded configuration concentrates clamping force, reducing stress concentration points. By meeting ASME B18.2.1 specifications, it provides consistent dimensional accuracy, while RoHS 3 and REACH compliance supports sustainable operations. Ideal for construction, manufacturing, and equipment maintenance, this screw delivers long-term durability and performance under extreme loads.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including Class 2A thread fit for consistent engagement and UNC coarse threading per inch-based measurements. It conforms to ASME B18.2.1 manufacturing specifications, ensuring interchangeability and reliability. The product is verified as RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting stringent environmental and safety regulations for industrial use.