S-90211A232 1/4"-20 x 2 1/2" SAE J429 Left-Hand Threaded High-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from zinc yellow-chromate plating extends service life in harsh industrial environments, minimizing maintenance needs.
• Precision Class 3A thread fit guarantees secure, vibration-resistant connections, enhancing assembly integrity.
• Left-hand UNC coarse threading provides effective fastening in specialized machinery where reverse rotation is required, preventing accidental loosening.
• High hardness (Rockwell C33) offers excellent wear resistance, maintaining thread integrity through repeated use.
• Full threading along the 2 1/2" length allows for adjustable grip and consistent holding power across various material thicknesses.
• External hex drive design enables easy installation with standard tools, speeding up assembly processes.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty and high-vibration settings, such as industrial machinery, automotive systems, and construction equipment. The left-hand UNC coarse thread is specifically designed for applications where standard right-hand threads may loosen under counter-clockwise forces, providing a secure fastening solution. Made from high-strength steel and finished with zinc yellow-chromate plating, it combats corrosion in demanding environments, reducing downtime and replacement costs. With a tensile strength of 150,000 psi and compliance with SAE J429 standards, it ensures durability and reliability, making it ideal for B2B procurement in sectors requiring robust, long-lasting fasteners.

Specification Summary & Compliance

This fastener adheres to precise dimensional standards, including a Class 3A thread fit for tight tolerances and UNC coarse threading (1/4"-20) with left-hand direction. It meets SAE J429 specifications for Grade 8 high-strength bolts, ensuring consistent quality and performance. The zinc yellow-chromate plating provides corrosion resistance, aligning with common industry requirements for environmental durability, though specific RoHS or REACH compliance should be verified per batch. Manufactured to deliver reliable thread diameter of 0.25" and length of 2 1/2", it supports engineering applications demanding exact fastening solutions.