S-91257A987 1"-8 x 12" 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 for reliable performance in high-stress applications
• Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh environments
• Optimized torque transmission through the external hex drive design, ensuring secure installation and removal
• Enhanced durability with Rockwell C33 hardness, maintaining structural integrity under repeated stress
• Secure fastening in various materials thanks to the 1"-8 UNC coarse thread configuration
• Reduced risk of thread stripping with Class 2A thread fit, providing consistent engagement and reliability
• Versatile partial threading allowing for both clamping and alignment functions in assembly applications

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical engineering solutions for heavy machinery, structural steel connections, and industrial equipment where failure is not an option. The combination of 150,000 PSI tensile strength and Rockwell C33 hardness ensures these fasteners maintain clamp load under extreme vibration and dynamic loads. The zinc yellow-chromate plating provides superior protection against corrosion in outdoor or chemically aggressive environments, significantly reducing maintenance frequency and replacement costs. The 1"-8 UNC coarse thread design enables rapid installation in steel frameworks and heavy-duty assemblies, while the partial threading allows for precise positioning and alignment in complex mechanical systems. These industrial fasteners are engineered to withstand the most demanding applications while maintaining consistent performance throughout their service life.

Specification Summary & Compliance

Manufactured to exacting standards with Class 2A thread fit tolerance and 1"-8 UNC coarse thread specifications. These hex head screws comply with ASME B18.2.1 and SAE J429 Grade 8 requirements, ensuring dimensional accuracy and mechanical properties. The fasteners are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, making them suitable for use in regulated industries and international markets. The 12" length with 2 1/2" minimum thread length provides optimal engagement for heavy-duty applications.