S-91257A864 3/4"-10 x 9" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance under extreme loads, reducing the risk of fastener failure in critical applications.
• Superior corrosion resistance from zinc yellow-chromate plating extends service life in harsh industrial environments, minimizing maintenance and replacement costs.
• High hardness rating (Rockwell C33) provides excellent wear resistance and durability, maintaining fastener integrity through repeated use.
• Coarse UNC threading offers faster installation and better performance in materials where fine threads might strip or fail.
• Class 2A thread fit ensures consistent, reliable engagement with mating parts while allowing for easier assembly compared to tighter tolerance classes.
• Partially threaded design provides optimal clamping force distribution, preventing joint loosening in vibration-prone applications.
• External hex drive with substantial 1 1/8" head width enables high torque application using standard tools, speeding up installation and removal.

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical performance where structural integrity cannot be compromised. The steel construction combined with zinc yellow-chromate plating creates a robust barrier against corrosion in demanding environments like construction, heavy machinery, and industrial equipment. The 3/4"-10 UNC coarse thread configuration provides superior holding power in softer materials and faster installation times compared to fine-thread alternatives. With partial threading and right-hand orientation, these fasteners excel in applications requiring precise clamping force and vibration resistance. The external hex drive design ensures compatibility with standard tools while the substantial 9" length accommodates thick material assemblies. Engineered to meet the most rigorous industrial standards, these screws prevent costly downtime and maintenance in critical load-bearing applications.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit per UNC standards with 3/4"-10 coarse threading and 2" minimum thread length. Manufactured to ASME B18.2.1 specifications where applicable under SAE J429 for Grade 8 fasteners. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and workplace safety standards are met.