S-91283A276 1 1/4"-7 x 8" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With 100,000 psi tensile strength, this screw reliably handles high-stress applications without failure, ensuring long-term structural integrity.
• Superior Durability & Corrosion Resistance – Made from Grade 5 steel with Rockwell C19 hardness, it offers excellent wear resistance and longevity in demanding industrial environments.
• Easy Installation & Removal – The external hex drive and coarse UNC threads provide quick, secure fastening with standard tools, reducing assembly time and labor costs.
• Precision Thread Fit – Class 2A thread fit ensures consistent, reliable engagement with mating parts, minimizing the risk of cross-threading and loosening under vibration.
• Versatile Partial Threading – The partially threaded design allows for effective clamping over long spans, ideal for applications requiring both grip and shear strength.
• Compliance with Industry Standards – Meets ASME B18.2.1 and SAE J429 specifications, guaranteeing interchangeability and performance consistency in regulated projects.
• Environmentally Responsible Manufacturing – RoHS 3 and REACH compliant, ensuring safe use in various industries without hazardous substances.

Professional Applications & Engineering Value

This Grade 5 steel hex head screw is engineered to address critical challenges in heavy machinery, construction, and structural assemblies where vibration resistance and high load capacity are paramount. The 1 1/4"-7 UNC coarse thread design enhances grip in softer materials and resists loosening under dynamic stresses, while the partially threaded shank provides optimal clamping force over the 8" length. Its external hex drive allows for high-torque installation with common tools, speeding up maintenance and reducing downtime. Ideal for industrial applications such as equipment frames, conveyor systems, and steel fabrication, this fastener delivers reliable performance under 100,000 psi tensile strength, ensuring safety and durability in rigorous environments.

Specification Summary & Compliance

This hex head screw adheres to precise dimensional standards, including Class 2A thread fit for consistent assembly and UNC coarse threading with a 1 1/4"-7 size. Manufactured in accordance with ASME B18.2.1 and SAE J429 specifications, it ensures reliability and interchangeability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted substances for safe industrial use.