S-90550A710 1/4"-20 x 3/8" ASME B18.3, ASTM F879, MIL-DTL-18240 Venting Stainless Steel Hex-Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel construction, ideal for harsh industrial environments and outdoor applications.
• Precise Class 3A thread fit ensures reliable, vibration-resistant fastening and reduces the risk of loosening under stress.
• Efficient hex drive (5/32") allows for high-torque installation and removal, speeding up assembly and maintenance workflows.
• Vented design prevents pressure buildup and allows for drainage, making it suitable for pneumatic systems and fluid-handling equipment.
• Fully threaded shank provides maximum grip and load distribution along the entire 3/8" length for enhanced joint integrity.
• Standard 82° countersink angle ensures a flush, secure fit in prepared holes, improving aesthetics and safety.
• Compliance with major standards including ASME B18.3 guarantees consistent quality and interchangeability in professional applications.

Professional Applications & Engineering Value

Engineered for demanding environments, this 1/4"-20 UNC Flat Head Screw in 18-8 Stainless Steel addresses common industrial challenges like corrosion, vibration, and pressure differentials. The coarse UNC thread and Class 3A fit provide quick assembly and high resistance to shake-outs in machinery, enclosures, and structural frames. Its vented feature is critical in applications requiring pressure equalization or fluid drainage, such as in HVAC systems, automotive assemblies, and electronic casings. The hex drive and fully threaded design ensure secure, tamper-resistant fastening, reducing maintenance downtime and enhancing operational reliability across sectors like aerospace, manufacturing, and marine engineering.

Specification Summary & Compliance

This screw maintains precise Class 3A thread fit per UNC standards, with a diameter of 0.25" and coarse thread spacing. It is manufactured in accordance with ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring dimensional accuracy and performance consistency. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe usage in global supply chains.