S-91286A103 1/4"-20 x 5/8" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional strength for demanding applications with a tensile strength of 150,000 PSI, ensuring reliable performance under high stress and load conditions.
• Superior corrosion resistance provided by the zinc-flake coating, extending the fastener's service life in harsh industrial environments.
• High durability and wear resistance due to Rockwell C33 hardness, reducing the risk of stripping or deformation during installation and use.
• Easy and secure installation with an external hex drive and UNC coarse threading, allowing for quick assembly and strong holding power.
• Precise thread fit for reliable connections with Class 2A thread fit, minimizing the chance of cross-threading and ensuring consistent performance.
• Full threading for maximum grip along the entire 5/8" length, providing uniform clamping force and stability in assembled components.
• Compliance with industry standards including ASME B18.2.1 and SAE J429, guaranteeing quality and interoperability in various engineering applications.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, construction equipment, and automotive systems. The steel material combined with a zinc-flake coating offers robust protection against corrosion and environmental wear, reducing maintenance needs and downtime. With a UNC coarse thread and external hex drive, it ensures fast, secure fastening even in high-vibration environments, preventing loosening and enhancing safety. The fully threaded design and Class 2A thread fit provide consistent engagement and load distribution, making it ideal for applications requiring high tensile strength and reliability, from structural frameworks to precision engineering projects.

Specification Summary & Compliance

This fastener adheres to precise dimensional tolerances, including a Class 2A thread fit and UNC coarse threading standards. It meets manufacturing specifications under ASME B18.2.1 and SAE J429, ensuring consistent quality and performance. Additionally, it is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe usage in global industrial markets.