S-91247A901 7/8"-9 x 8 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance in high-stress industrial applications, reducing the risk of fastener failure.
• Zinc plating provides superior corrosion resistance, extending the screw's service life in harsh or outdoor environments.
• Grade 5 steel construction with Rockwell C25 hardness offers an optimal balance of strength and durability for demanding fastening tasks.
• Coarse UNC threading and Class 2A thread fit enable faster installation and secure holding power, even in softer materials.
• External hex drive and large head dimensions allow for high-torque application with standard tools, simplifying assembly and maintenance.
• Partial threading design provides an unthreaded shank for enhanced shear strength where needed in structural connections.
• Compliance with ASME, SAE, RoHS, and REACH standards guarantees consistent quality, safety, and environmental responsibility.

Professional Applications & Engineering Value

This 7/8"-9 UNC Grade 5 steel hex head screw is engineered to address critical challenges in heavy machinery, construction, and structural steelwork. Its coarse thread and Class 2A fit ensure rapid, secure fastening in applications where vibration resistance and load distribution are paramount. The zinc plated finish combats corrosion, making it suitable for outdoor or humid conditions without compromising the 120,000 psi tensile strength. The partially threaded design enhances resistance to shear forces, ideal for bolted joints that experience dynamic loads. By meeting ASME B18.2.1 and SAE J429 specifications, it delivers predictable performance for engineers and procurement teams seeking reliable, code-compliant industrial fasteners.

Specification Summary & Compliance

This screw adheres to Class 2A thread fit tolerances per UNC standards, with a thread size of 7/8"-9 and a minimum thread length of 2 1/4". It is manufactured in compliance with ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and mechanical properties. The product is also verified as RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming it meets strict environmental and safety regulations for hazardous substances.