S-91283A330 1 1/4"-12 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 of 100,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Grade 5 steel construction with Rockwell C19 hardness provides superior durability and resistance to wear, extending service life in demanding environments.
• 1 1/4"-12 UNF fine threading with Class 2A fit offers precise engagement and vibration resistance, maintaining joint integrity over time.
• Partially threaded design with 3" minimum thread length allows for focused clamping force and easier alignment in assembled components.
• External hex drive and hex head facilitate quick installation and high torque application with standard tools, improving assembly efficiency.
• Compliance with ASME B18.2.1 and SAE J429 standards guarantees consistent quality and interoperability in industrial systems.
• RoHS 3 and REACH compliant ensures environmental safety and regulatory adherence for global supply chain use.

Professional Applications & Engineering Value

This Grade 5 steel hex head screw is engineered to address critical challenges in heavy machinery, construction, and automotive assemblies where high tensile strength and vibration resistance are paramount. The 1 1/4"-12 UNF fine thread and Class 2A fit provide secure fastening in dynamic loads, minimizing loosening in equipment subjected to constant stress. Its partially threaded shank concentrates clamping force on specific sections, ideal for bolting flanges or structural frames that require precise load distribution. Made from hardened steel with a Rockwell C19 rating, it withstands harsh conditions without compromising integrity, while the external hex drive ensures compatibility with common wrenches for streamlined maintenance. By meeting ASME B18.2.1 specifications, it delivers reliability in industrial hex bolt applications, from conveyor systems to engine mounts, enhancing overall assembly durability.

Specification Summary & Compliance

This fastener adheres to inch system dimensions with a thread size of 1 1/4"-12 UNF, fine thread spacing, and a Class 2A thread fit for precise tolerance per UNF standards. It complies with ASME B18.2.1 and SAE J429 manufacturing specifications, ensuring consistent performance. Regulatory conformity includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) for environmental safety, supporting use in regulated industries.