S-91268A227 1 1/4"-7 x 8" 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 150,000 psi tensile strength and Grade 8 classification for reliable performance in high-stress applications
• Superior wear resistance due to Rockwell C33 hardness, ensuring extended service life and reduced replacement frequency
• Optimized thread engagement through UNC coarse threading with Class 2A fit, providing secure fastening and vibration resistance
• Enhanced installation efficiency with external hex drive and 1 7/8" head width, allowing for standard tool compatibility and high torque application
• Versatile partial threading design offering both gripping strength and clearance flexibility for varied industrial assembly requirements
• Regulatory compliance assurance meeting ASME B18.2.1, RoHS 3, and REACH standards for global industrial use and environmental safety
• Robust material integrity from steel construction, delivering consistent performance across temperature variations and harsh operating conditions

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these Grade 8 hex head screws address critical challenges in heavy machinery, structural steel connections, and equipment manufacturing. The 1-1/4"-7 UNC coarse thread configuration combined with Class 2A thread fit ensures rapid assembly while maintaining vibration resistance in dynamic load applications. The partially threaded design provides optimal clamp force distribution, preventing joint loosening in construction equipment, transportation systems, and industrial platforms. With 150,000 psi tensile strength and external hex drive compatibility, these fasteners deliver reliable performance where structural integrity and maintenance accessibility are paramount, making them ideal for OEM manufacturing and MRO operations requiring ASME B18.2.1 compliant solutions.

Specification Summary & Compliance

Manufactured to precise inch system dimensions with Class 2A thread fit tolerance per UNC standards. Complies with ASME B18.2.1 specifications where identified under SAE J429, ensuring dimensional consistency and mechanical performance. Meets RoHS 3 (2015/863/EU) compliance for restricted substance control and REACH (EC 1907/2006) regulations regarding chemical substance management. The Grade 8 strength classification and Rockwell C33 hardness validate consistent mechanical properties across production batches.