S-91286A368 1/2"-20 x 1 1/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum Load Capacity: With a 150,000 PSI tensile strength and Rockwell C33 hardness, this screw provides exceptional resistance to stretching and breaking under extreme loads.
• Superior Corrosion Protection: The zinc-flake coating offers excellent defense against rust and corrosion, extending the fastener's service life in harsh environments.
• Reliable, Secure Fastening: The fully threaded design and 1/2"-20 UNF fine thread pattern ensure maximum grip and vibration resistance in critical assemblies.
• High-Strength Grade 8 Assurance: Manufactured to Grade 8 standards, guaranteeing consistent performance for the most demanding heavy-duty applications.
• Precision Fit and Easy Installation: The Class 2A thread fit and standard external hex drive head allow for accurate, straightforward installation with common tools.
• Broad Industrial Compliance: Meets ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and mechanical reliability.
• Environmentally Responsible Manufacturing: Compliant with RoHS 3 and REACH regulations, making it a safe choice for regulated industries.

Professional Applications & Engineering Value

Engineered for high-stress environments, this Grade 8 hex head screw is the ideal solution for industrial applications where failure is not an option. Its 150,000 PSI tensile strength and Rockwell C33 hardness directly address the need for fasteners that can withstand intense vibrational forces and heavy loads without deforming. The zinc-flake coated steel construction provides a critical barrier against corrosion, significantly reducing maintenance needs and replacement costs in outdoor or chemically aggressive settings. The 1/2"-20 UNF fine thread and fully threaded design ensure a superior hold in tapped holes, preventing loosening in machinery, structural steel frames, and heavy equipment assemblies. This combination of material strength, protective finish, and precise external hex drive design delivers long-term reliability and safety for engineers and procurement specialists.

Specification Summary & Compliance

This fastener features a 1/2"-20 UNF thread with a Class 2A fit for consistent, precise engagement. It is manufactured in compliance with the dimensional and mechanical specifications of ASME B18.2.1 and SAE J429 for Grade 8 fasteners. The product is also verified to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, adhering to strict environmental and safety standards for industrial components.