S-90211A426 3/4"-10 x 2 1/2" SAE J429 Left-Hand Threaded High-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum load-bearing capacity with 150,000 psi tensile strength and Grade 8 classification for demanding industrial applications
• Superior corrosion protection through zinc yellow-chromate plating that extends service life in harsh environments
• Precise thread engagement with Class 3A fit and UNC coarse threading ensuring reliable fastening performance
• Exceptional hardness durability with Rockwell C33 rating that maintains structural integrity under heavy vibration
• Left-hand threading advantage for specialized applications requiring reverse-direction security and anti-loosening properties
• Full-threaded design efficiency providing maximum grip length and uniform stress distribution along the entire fastener
• Heavy-duty hex head configuration with 1-1/8" width offering superior torque transmission and wrench accessibility

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical performance in heavy machinery, construction equipment, and industrial assemblies where left-hand threading prevents unintended loosening from rotational forces. The steel construction with zinc yellow-chromate plating combats corrosion in outdoor and high-moisture environments, while the UNC coarse thread pattern with Class 3A fit ensures rapid installation and vibration resistance. Engineered to SAE J429 specifications, these fully threaded fasteners provide uniform clamping force across the entire 2-1/2" length, making them ideal for structural connections, equipment maintenance, and applications requiring high tensile strength with reliable disassembly capabilities.

Specification Summary & Compliance

This 3/4"-10 UNC left hand hex head screw features Class 3A thread fit precision and coarse thread spacing for optimal performance. Manufactured from high-strength steel with Rockwell C33 hardness and 150,000 psi tensile strength, the fastener complies with SAE J429 specifications for Grade 8 requirements. The zinc yellow-chromate plating provides corrosion resistance while meeting industry standards for heavy-duty applications. Dimensions include 2-1/2" length, 1-1/8" head width, and 1/2" head height with external hex drive configuration.