S-91268A931 1"-8 x 4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with Grade 8 classification and 150,000 PSI tensile strength, ensuring reliable performance in high-stress industrial applications.
• Superior wear resistance due to Rockwell C33 hardness, extending service life and reducing replacement frequency in demanding environments.
• Precise and secure fastening with Class 2A thread fit and UNC coarse threading, providing excellent grip and vibration resistance for heavy machinery.
• Optimized for heavy-duty use featuring a 1 1/2" hex head and external drive style, allowing for high torque application and easy installation with standard tools.
• Enhanced load distribution through partial threading and 4" length, minimizing stress concentration and improving joint integrity in structural assemblies.
• Compliance with industry standards including ASME B18.2.1 and SAE J429, guaranteeing consistent quality and interoperability in mechanical systems.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, ensuring safety and regulatory adherence for global supply chains.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, this Grade 8 hex head screw addresses critical challenges in machinery, construction, and automotive sectors where high tensile strength and vibration resistance are paramount. The steel material and Rockwell C33 hardness provide exceptional durability against wear and fatigue, while the 1"-8 UNC coarse thread and Class 2A fit ensure rapid assembly and reliable clamping force in coarse-alignment scenarios. Partial threading optimizes stress distribution along the 4" shank, reducing the risk of thread stripping under dynamic loads. Ideal for external hex drive setups, it facilitates efficient maintenance in confined spaces, supporting operational uptime and safety in extreme conditions.

Specification Summary & Compliance

This fastener adheres to inch system measurements with precise dimensions: 1"-8 UNC thread size, Class 2A thread fit for consistent tolerance, and 4" length. It meets ASME B18.2.1 and SAE J429 specifications for mechanical properties, ensuring reliability in high-strength bolt applications. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) confirms environmental safety, free from restricted substances, making it suitable for regulated industrial markets.