S-91268A903 7/8"-9 x 4" 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 in high-stress industrial applications, reducing the risk of fastener failure.
• High Rockwell C33 hardness provides superior resistance to wear and deformation, extending service life in demanding environments.
• Coarse UNC threads offer faster installation and better grip in softer materials, enhancing assembly efficiency and clamping force.
• Partially threaded design allows for precise tension control and secure fastening in structural joints without unnecessary thread engagement.
• Grade 8 steel construction delivers excellent durability and fatigue resistance, ideal for heavy machinery and equipment.
• Class 2A thread fit ensures consistent, easy assembly with standard nuts while maintaining tight tolerances for vibration resistance.
• External hex drive enables high-torque application with common tools, simplifying maintenance and reducing installation time.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, this Grade 8 hex head screw addresses critical challenges in construction, machinery, and automotive sectors where high tensile strength and vibration resistance are paramount. The 7/8"-9 UNC coarse thread design ensures rapid installation and robust clamping in structural steel, while the partially threaded shank minimizes stress concentration points. Made from high-grade steel with Rockwell C33 hardness, it withstands extreme loads and repetitive stress, preventing loosening in dynamic environments. Compliant with ASME B18.2.1 and SAE J429 standards, it guarantees precision and reliability for engineers requiring consistent performance in critical assemblies.

Specification Summary & Compliance

This 4" length hex head screw features a 7/8"-9 UNC coarse thread with Class 2A thread fit for precise dimensional accuracy and easy assembly. Manufactured to meet ASME B18.2.1 and SAE J429 specifications, it ensures consistent quality and performance. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe industrial use.