S-91286A226 3/8"-16 x 4 1/2" 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 the zinc-flake coating extends service life in harsh environments, minimizing maintenance and replacement costs.
• High hardness rating (Rockwell C33) provides excellent wear resistance and durability, maintaining thread integrity through repeated use.
• Partially threaded design allows for secure clamping on unthreaded sections while providing optimal grip length for versatile assembly needs.
• Class 2A thread fit with UNC coarse threading enables quick installation and reliable engagement, reducing assembly time and improving productivity.
• External hex drive with standard 9/16" head width offers familiar, tool-friendly installation compatible with common wrenches for efficient maintenance.
• Full compliance with industry standards including ASME B18.2.1 and SAE J429 ensures consistent quality and interchangeability in professional applications.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these Grade 8 hex head screws deliver exceptional performance where failure is not an option. The steel construction combined with 150,000 PSI tensile strength makes them ideal for heavy machinery, structural steel connections, and high-vibration equipment where reliability under extreme stress is critical. The zinc-flake coated finish provides superior protection against corrosion in outdoor or chemically aggressive environments, significantly extending service life. With 3/8"-16 UNC coarse threading and partial threading design, these fasteners offer optimal clamping force distribution while resisting loosening in dynamic load conditions. These industrial-grade screws solve common engineering challenges by combining high strength with corrosion resistance, ensuring long-term structural integrity in construction, manufacturing, and heavy equipment applications.

Specification Summary & Compliance

This Grade 8 hex head screw features precise Class 2A thread fit with 3/8"-16 UNC coarse threading and 4 1/2" length with minimum 1" thread engagement. Manufactured to ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and performance consistency. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industries and applications.