S-91268A837 5/8"-11 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 capability with 150,000 PSI tensile strength for reliable performance in high-stress applications
• Superior hardness and durability from Rockwell C33 hardened steel construction, resisting wear and deformation
• Secure fastening with precise thread engagement thanks to Class 2A UNC coarse threads and partial threading design
• Easy installation and removal with external hex drive and 15/16" head width for standard wrench compatibility
• Compliance with major industry standards including ASME B18.2.1 and SAE J429 for guaranteed quality and interchangeability
• Environmental regulation adherence with RoHS 3 and REACH compliance for safe use in regulated industries
• Optimized for heavy machinery and structural applications with 8" length providing substantial clamping range

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these Grade 8 hex head screws deliver critical reliability where failure is not an option. The 5/8"-11 UNC coarse thread configuration ensures rapid assembly while maintaining exceptional clamping force in structural steel connections, heavy equipment manufacturing, and machinery foundations. The partially threaded design concentrates strength where needed most, while the external hex drive accommodates high-torque installation with standard tools. Manufactured from high-strength steel with controlled hardness, these fasteners withstand vibration, shock loads, and extreme tension without compromising integrity. Ideal for construction, mining equipment, and industrial machinery where 150,000 PSI tensile strength and Rockwell C33 hardness provide the margin of safety required for critical connections.

Specification Summary & Compliance

This 8" hex head screw features 5/8"-11 UNC coarse threads with Class 2A thread fit ensuring proper clearance and engagement. Manufactured to ASME B18.2.1 and SAE J429 Grade 8 specifications with partial threading extending 1½" minimum. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The inch system measurement provides head dimensions of 25/64" height and 15/16" width with external hex drive configuration.