S-91268A140 5/16"-18 x 1 1/4" 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, ideal for high-stress industrial applications.
• Superior wear resistance due to Rockwell C33 hardness, ensuring long service life and reduced replacement frequency.
• Reliable fastening performance with fully threaded 5/16"-18 UNC coarse thread design, providing excellent grip and vibration resistance.
• Easy installation and removal featuring an external hex drive and standard right-hand thread, compatible with common tools for efficient maintenance.
• Precise thread fit with Class 2A tolerance, ensuring consistent engagement and reducing the risk of cross-threading or loosening.
• Compliance with industry standards including ASME B18.2.1 and SAE J429, guaranteeing quality and interoperability in mechanical assemblies.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, meeting strict regulations for hazardous substance control.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial environments, such as machinery, automotive, and construction assemblies. Made from high-strength steel and featuring a fully threaded UNC coarse thread design, it delivers superior clamping force and resistance to dynamic loads, preventing joint failure under extreme conditions. The external hex drive allows for quick, secure tightening with standard wrenches, reducing installation time and labor costs. Its 150,000 PSI tensile strength and Rockwell C33 hardness ensure it withstands high stress and abrasion, making it a reliable choice for applications where safety and durability are paramount, such as in structural frames, engine components, and heavy equipment.

Specification Summary & Compliance

This fastener adheres to precise dimensional standards, including Class 2A thread fit for consistent accuracy and UNC coarse threading (5/16"-18) for robust performance. It meets ASME B18.2.1 and SAE J429 specifications, ensuring reliability in mechanical systems. Additionally, it is certified RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming adherence to environmental and safety regulations for industrial use.