S-91286A342 1/2"-13 x 3 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Capacity: With a 150,000 psi tensile strength and Grade 8 classification, this screw reliably handles extreme stress and heavy-duty applications, reducing the risk of fastener failure.
• Superior Corrosion Protection: The Zinc-Flake coating offers excellent resistance to rust and environmental degradation, ensuring long-term reliability in harsh industrial settings.
• Optimized for High-Torque Installation: The external hex head design provides a secure grip for standard wrenches, enabling efficient installation and removal with common tools.
• Enhanced Durability and Wear Resistance: A Rockwell C33 hardness rating ensures the screw maintains its structural integrity and resists deformation under heavy loads.
• Reliable Thread Engagement: Coarse UNC threads and a Class 2A thread fit facilitate easier alignment and faster assembly while maintaining secure connections.
• Versatile Partial Threading: The partially threaded shank allows for unthreaded grip length, providing superior clamping force where needed in structural assemblies.
• Compliance and Quality Assurance: Manufactured to meet ASME B18.2.1 and SAE J429 standards, ensuring consistent quality, dimensional accuracy, and performance reliability.

Professional Applications & Engineering Value

This Grade 8 Hex Head Screw is engineered to solve critical challenges in demanding industrial environments. Its high-strength steel construction and 150,000 psi tensile strength make it ideal for heavy machinery, structural steel connections, and automotive assemblies where failure is not an option. The Zinc-Flake coating provides a robust barrier against corrosion, significantly extending service life in outdoor or chemically aggressive settings. Featuring a coarse UNC 1/2"-13 thread and external hex drive, it ensures quick, secure installation with standard tools, reducing assembly time and labor costs. The partially threaded design offers precise clamping control, making it a top choice for applications requiring vibration resistance and sustained structural integrity under dynamic loads.

Specification Summary & Compliance

This screw adheres to precise dimensional standards with a Class 2A thread fit for consistent engagement and a 3 3/4" length with a 1 1/4" minimum thread length. It conforms to ASME B18.2.1 and SAE J429 specifications for Grade 8 fasteners. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets stringent environmental and safety standards for industrial use.