S-91268A340 1 1/4"-12 x 8" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum Load-Bearing Capacity - Grade 8 steel construction and 150,000 psi tensile strength ensure reliable performance in the most demanding industrial applications.
• Superior Thread Engagement - Fine 1 1/4"-12 UNF threads with Class 2A fit provide excellent vibration resistance and secure fastening.
• Enhanced Durability - Rockwell C33 hardness offers exceptional wear resistance and long-term reliability under heavy use.
• Optimized Installation Efficiency - External hex drive with 1 7/8" head width allows for high-torque application using standard tools.
• Versatile Fastening Solution - Partially threaded 8" length design provides both clamping force and unthreaded shank strength where needed.
• Industry Compliance Assurance - Meets ASME B18.2.1 and SAE J429 standards, ensuring dimensional accuracy and performance reliability.
• Environmental Responsibility - RoHS 3 and REACH compliant for safe use in regulated industrial environments.

Professional Applications & Engineering Value

These Grade 8 steel hex head screws deliver exceptional engineering value in heavy machinery, structural steel connections, and industrial equipment assembly. The 1 1/4"-12 UNF fine thread configuration provides superior resistance to vibration loosening, critical in dynamic load applications. The partially threaded design combines the benefits of a smooth shank for shear strength with threaded engagement for precise clamping force. With 150,000 psi tensile strength and Rockwell C33 hardness, these fasteners solve critical challenges in applications requiring both high strength and durability. The external hex drive ensures reliable installation even in high-torque scenarios, making them ideal for construction equipment, mining machinery, and heavy industrial frameworks where failure is not an option.

Specification Summary & Compliance

This heavy-duty hex head screw features precise Class 2A thread fit with 1 1/4"-12 UNF fine threading and minimum 3" thread length. Manufactured to ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and mechanical performance. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for global industrial applications requiring strict material compliance.