S-91785A558 1/4"-28 x 5/8" ASME B18.6.3 Stainless Steel Truss Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to 18-8 stainless steel construction and passivated finish, ideal for harsh environments
• Exceptional holding power with 100,000 psi tensile strength and Rockwell B100 hardness for reliable, long-term fastening
• Enhanced load distribution from the wide rounded truss head design, reducing surface pressure and material damage
• Precise thread engagement with Class 2A fit and UNF fine threading, ensuring secure connections in critical applications
• Full-threaded design for maximum grip along the entire 5/8" length, improving fastener stability
• Broad regulatory compliance including ASME B18.6.3, RoHS 3, and REACH, guaranteeing safety and environmental standards
• Easy installation and removal with a simple slotted drive, compatible with standard tools

Professional Applications & Engineering Value

This 18-8 stainless steel rounded truss head screw is engineered to address common industrial challenges such as vibration loosening, corrosion-induced failure, and uneven load distribution. The UNF fine thread (1/4"-28) and Class 2A thread fit provide superior resistance to loosening under dynamic loads, making it ideal for machinery, automotive assemblies, and electronic enclosures. The passivated finish enhances the natural corrosion resistance of stainless steel, extending service life in humid or chemically aggressive environments. Its wide truss head distributes clamping force over a larger area, preventing damage to soft materials and ensuring a secure fit in applications requiring wide-bearing surfaces. Fully compliant with ASME B18.6.3 and environmental regulations, this screw delivers reliability and compliance for demanding B2B and industrial uses.

Specification Summary & Compliance

This screw features a 1/4"-28 UNF fine thread with Class 2A thread fit for precise dimensional accuracy. It is manufactured in accordance with ASME B18.6.3 specifications, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of hazardous substances and safe for various industrial applications.