S-91257A981 1"-8 x 9" 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, ideal for heavy-duty structural applications
• Superior corrosion resistance from zinc yellow-chromate plating, extending service life in harsh environments
• Reliable high-strength performance meeting Grade 8 standards with Rockwell C33 hardness for consistent durability
• Optimized coarse threading (1"-8 UNC) providing faster installation and superior resistance to vibration loosening
• Precision Class 2A thread fit ensuring smooth assembly and consistent clamping force in industrial equipment
• Versatile partial threading design allowing both secure fastening and adjustable positioning in structural connections
• Full regulatory compliance with ASME B18.2.1, RoHS 3, and REACH standards for global industrial applications

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical engineering solutions for heavy machinery, structural steel frameworks, and industrial equipment where failure is not an option. The 1"-8 UNC coarse thread configuration provides exceptional resistance to vibrational loosening while enabling rapid installation in time-sensitive maintenance operations. The zinc yellow-chromate plating creates a robust barrier against corrosion in manufacturing environments exposed to moisture, chemicals, and temperature variations. With partial threading design, these fasteners offer precise load distribution across both threaded and unthreaded sections, preventing joint failure in high-stress applications. Engineered to ASME B18.2.1 specifications and SAE J429 Grade 8 requirements, they provide dependable performance in construction, mining equipment, and heavy vehicle assembly where maximum tensile strength and reliability are paramount.

Specification Summary & Compliance

Manufactured to precise Class 2A thread fit tolerances with 1"-8 UNC coarse thread specifications ensuring consistent engagement and optimal clamping force. These hex head screws comply with ASME B18.2.1 dimensional standards and SAE J429 Grade 8 mechanical properties. The fasteners maintain full compliance with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations for chemical safety, making them suitable for global industrial supply chains and environmentally conscious manufacturing operations.