S-92949A842 1/4"-28 x 9/16" ASME B18.3, ASTM F879 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel and passivated finish, ideal for harsh environments and extended service life.
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance under high stress.
• Precise and secure fastening ensured by Class 3A thread fit and UNF fine threads, minimizing the risk of loosening in vibration-prone applications.
• Efficient installation and removal with a 5/32" hex drive and rounded button head, allowing for easy access and high torque application.
• Full thread engagement across the entire 9/16" length provides maximum grip and load distribution in assembled components.
• Compliance with major industry standards including ASME B18.3, ensuring dimensional accuracy and interchangeability.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, meeting global regulatory requirements for hazardous substances.

Professional Applications & Engineering Value

This 1/4"-28 UNF rounded head screw is engineered to address critical challenges in precision assemblies. Manufactured from 18-8 Stainless Steel with a passivated finish, it provides excellent resistance to oxidation and chemical exposure, making it suitable for applications in marine, chemical processing, and food equipment where corrosion resistance is paramount. The Class 3A thread fit and fine UNF threading deliver superior clamping force and vibration resistance, essential for maintaining integrity in dynamic or high-stress environments like automotive subsystems and aerospace fixtures. The hex drive design ensures reliable torque transmission, reducing the risk of stripping and enabling efficient maintenance in confined spaces. These features collectively enhance assembly reliability, reduce lifecycle costs, and support stringent quality requirements in industrial and OEM settings.

Specification Summary & Compliance

This screw adheres to precise dimensional and performance criteria, including a Class 3A thread fit for tight tolerances and a UNF (Unified National Fine) thread form. It is manufactured in compliance with the ASME B18.3 specification, ensuring consistent quality and interchangeability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted hazardous substances and supporting sustainable procurement practices.