S-91943A561 5/16"-18 x 3/4" Set Screws

Key Features & Benefits at a Glance

• Enhanced Fastening Precision – Permanent swivel tip with 9° maximum angle ensures optimal contact and grip, reducing component slippage in dynamic applications.
• Superior Corrosion Resistance – Black-oxide coating on alloy steel provides durable protection against rust and wear in harsh industrial environments.
• High Mechanical Strength – Rockwell C39 hardness rating delivers reliable load-bearing capacity and resistance to deformation under stress.
• Easy Installation & Removal – Hex drive (5/32") allows for straightforward torque application with standard tools, minimizing assembly time.
• Accurate Thread Engagement – UNC coarse threads with Class 2A fit ensure consistent, secure fastening and compatibility with standard mating components.
• Space-Saving Headless Design – Ideal for confined assemblies where protruding fastener heads are not feasible.
• Regulatory Compliance Assurance – Meets RoHS 3 and REACH standards, supporting sustainable and safe manufacturing practices.

Professional Applications & Engineering Value

This 5/16"-18 UNC set screw is engineered to address critical challenges in precision machinery, automotive systems, and heavy equipment assembly. The permanent swivel tip technology distributes clamping force evenly, preventing damage to shaft surfaces and maintaining alignment under vibration—a common issue in rotating components. Made from black-oxide alloy steel, it combines high tensile strength with corrosion resistance, ensuring longevity in demanding conditions. The coarse UNC thread and Class 2A fit facilitate quick installation while providing reliable thread retention, reducing the risk of loosening in high-torque applications. Its headless, hex-drive design is particularly valuable in compact spaces, such as motor couplings and gear assemblies, where accessibility and flush mounting are essential for operational safety and efficiency.

Specification Summary & Compliance

This set screw adheres to UNC thread standards with a Class 2A thread fit for precise dimensional accuracy and interchangeability. Key specifications include a 5/16"-18 thread size, 3/4" length, and 5/32" hex drive. The product is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for global industrial use.