S-91783A114 4-40 x 7/8" ASME B18.6.3 Stainless Steel Round Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Exceptional mechanical strength with 100,000 psi tensile strength and Rockwell B100 hardness for reliable performance under high stress
• Precision threading with Class 2A fit and UNC coarse thread profile ensuring secure fastening and vibration resistance
• Universal compatibility through full compliance with ASME B18.6.3 standards for interchangeability across industrial systems
• Enhanced installation control with slotted drive and rounded head design for straightforward assembly and disassembly
• Environmental compliance meeting RoHS 3 and REACH regulations for safe use in regulated industries
• Full-thread engagement along the entire 7/8" length for maximum grip strength and load distribution

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these 4-40 UNC rounded head slotted screws provide critical solutions for machinery assembly, electronic enclosures, and precision equipment. The 18-8 stainless steel composition combined with passivated finish creates a robust barrier against chemical exposure and atmospheric corrosion, significantly reducing maintenance frequency in manufacturing environments. The coarse thread design ensures rapid installation while maintaining holding power in softer materials, and the Class 2A thread fit guarantees consistent performance across production runs. These fully threaded fasteners deliver reliable clamping force distribution across the entire 7/8" length, making them ideal for applications requiring uniform pressure distribution and vibration resistance in automotive, aerospace, and industrial control systems.

Specification Summary & Compliance

This 4-40 UNC screw features precision Class 2A thread fit tolerances with right-hand threading and coarse thread spacing. Manufacturing conforms to ASME B18.6.3 specifications, ensuring dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting the latest standards for hazardous substance restrictions and chemical safety in industrial applications.