S-92316A832 5/8"-18 x 4" IFI 111, SAE J429 High-Strength Grade 8 Steel Flanged Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Strength for Heavy-Duty Applications: Grade 8 classification and 150,000 psi tensile strength ensure reliable performance under extreme loads and vibrations.
• Superior Corrosion Resistance: Black-phosphate steel finish provides a durable protective layer, extending the screw's service life in harsh industrial environments.
• Precision Threading for Secure Fastening: UNF fine thread with Class 2A fit guarantees tight, secure connections and reduces the risk of loosening.
• Enhanced Stability with Flange Design: Integrated flange acts as a built-in washer, distributing clamp load evenly and preventing pull-through in assembled materials.
• Optimized for High-Strength Requirements: Rockwell C32 hardness provides excellent wear resistance and durability, maintaining integrity in demanding mechanical systems.
• Efficient Installation and Removal: External hex drive and 15/16" head width allow for high-torque application with standard tools, speeding up assembly processes.
• Versatile Partial Threading: The 1 1/2" minimum threaded length on a 4" shank provides flexibility for applications requiring both clamped and unclamped sections.

Professional Applications & Engineering Value

This Grade 8 Hex Head Screw is engineered to solve critical fastening challenges in heavy machinery, construction, and automotive assemblies. The black-phosphate steel material offers superior corrosion resistance, which is vital for equipment exposed to moisture, chemicals, or outdoor conditions. Its UNF fine thread and Class 2A thread fit ensure precise engagement, minimizing the risk of cross-threading and providing consistent clamp load in high-vibration environments. The flanged design eliminates the need for a separate washer, reducing part count and assembly time while increasing joint stability. These features make it an ideal choice for structural frames, engine components, and industrial machinery where failure is not an option. The partially threaded shank allows the unthreaded portion to act as a precision dowel, resisting shear forces and maintaining alignment in dynamic applications.

Specification Summary & Compliance

This screw adheres to stringent dimensional and performance standards, including Class 2A thread fit for consistent assembly and UNF fine thread specifications. It is manufactured in compliance with IFI 111 / SAE J429 for Grade 8 mechanical properties, ensuring 150,000 psi tensile strength and Rockwell C32 hardness. The product is also verified to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting global environmental and safety regulations for industrial use.