S-91286A307 7/16"-20 x 3" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance with zinc-flake coating extends service life in harsh industrial environments, minimizing maintenance needs.
• High hardness rating (Rockwell C33) provides excellent wear resistance, maintaining thread integrity over repeated use.
• Precision UNF fine threads with Class 2A fit offer secure, vibration-resistant connections in critical assemblies.
• Partially threaded design allows for controlled clamping force and easier installation in specific applications.
• External hex drive enables high-torque installation with standard tools, speeding up assembly processes.
• Compliance with industry standards including ASME B18.2.1 and SAE J429 guarantees consistent quality and interchangeability.

Professional Applications & Engineering Value

These Grade 8 hex head screws are engineered to address demanding fastening challenges in heavy machinery, construction equipment, and automotive systems. The zinc-flake coated steel construction provides exceptional corrosion protection in outdoor or chemically aggressive environments, while the UNF fine thread configuration ensures superior vibration resistance in dynamic applications. The partially threaded design allows for precise load distribution, making them ideal for components requiring both clamping and alignment functions. With 150,000 psi tensile strength and Rockwell C33 hardness, these fasteners maintain integrity under extreme mechanical stress, reducing downtime and replacement costs in industrial operations.

Specification Summary & Compliance

This 7/16"-20 UNF hex head screw features Class 2A thread fit for precise dimensional accuracy and meets ASME B18.2.1 and SAE J429 manufacturing specifications. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industrial sectors. With a 3" length and partial threading beginning at 1-1/8" minimum thread length, it maintains consistent performance in inch system applications requiring heavy-duty fastening solutions.