S-91257A983 1"-8 x 9 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum load-bearing capacity with 150,000 psi tensile strength and Grade 8 classification for critical structural applications
• Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh industrial environments
• Optimized thread engagement through 1"-8 UNC coarse threading that resists vibration loosening and enables faster installation
• Precise mechanical performance ensured by Rockwell C33 hardness and Class 2A thread fit for consistent torque-tension relationships
• Enhanced installation efficiency with external hex drive design that accommodates standard tools and provides reliable torque transfer
• Reduced assembly weight through partial threading while maintaining full strength in the engaged section
• Regulatory compliance assurance meeting ASME B18.2.1, RoHS 3, and REACH standards for global industrial applications

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver exceptional engineering value in demanding applications where failure is not an option. The 1"-8 UNC coarse thread configuration provides superior resistance to vibrational loosening in heavy machinery, construction equipment, and structural steel connections. The zinc yellow-chromate plating creates a robust barrier against corrosion in outdoor or chemically aggressive environments, significantly extending maintenance intervals. With 150,000 psi tensile strength and Rockwell C33 hardness, these fasteners maintain clamp load under extreme conditions, preventing joint failure in critical assemblies. The external hex drive design ensures compatibility with standard industrial tools while the partial threading optimizes weight distribution without compromising strength where it matters most.

Specification Summary & Compliance

Manufactured to exacting ASME B18.2.1 specifications and SAE J429 Grade 8 requirements, these hex head screws feature precision Class 2A thread fit for consistent assembly performance. The 1"-8 UNC coarse thread maintains proper engagement while the 9½" length provides versatile application coverage. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations ensures environmental responsibility and global market acceptance for industrial procurement.