S-91257A740 1/2"-13 x 8" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 psi tensile strength for critical structural applications
• Superior corrosion resistance through zinc yellow-chromate plating in demanding environments
• Optimized torque transmission via external hex drive design for secure installation
• Enhanced durability with Rockwell C33 hardness to withstand vibration and impact
• Reliable thread engagement with Class 2A fit and coarse UNC threading for faster assembly
• Versatile partial threading allowing for both clamping and alignment functions
• Industry-standard compliance meeting ASME B18.2.1 and SAE J429 specifications

Professional Applications & Engineering Value

This Grade 8 hex head screw delivers critical performance in heavy machinery, structural steel connections, and industrial equipment where failure is not an option. The steel construction with zinc yellow-chromate plating provides essential corrosion protection in harsh operating conditions, while the coarse UNC threading ensures rapid assembly and superior vibration resistance. The partially threaded design offers precise clamping control, making it ideal for applications requiring both secure fastening and alignment adjustment. Engineered to withstand extreme mechanical stress, this 1/2"-13 x 8" fastener maintains integrity under sustained heavy loads, reducing maintenance frequency and downtime in construction and manufacturing environments.

Specification Summary & Compliance

This Grade 8 hex head screw features precise Class 2A thread fit with 1/2"-13 UNC coarse threading and partial threading over 1½" minimum length. Manufactured to ASME B18.2.1 and SAE J429 specifications, it ensures dimensional accuracy and mechanical reliability. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting the latest industry standards for hazardous substance restrictions.