S-91857A844 4-40 x 1/2" ASME B18.6.3 Stainless Steel Round Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance in harsh environments thanks to 316 stainless steel construction and passivated surface treatment
• Exceptional mechanical strength with 100,000 psi tensile strength and Rockwell B100 hardness for reliable load-bearing performance
• Precise thread engagement with Class 2A fit and UNC coarse spacing ensuring secure fastening and vibration resistance
• Full-length threading provides maximum grip and consistent holding power across the entire fastener length
• Industry-standard compliance with ASME B18.6.3 specifications for dimensional accuracy and interchangeability
• Easy installation and removal with standard slotted drive design compatible with common hand tools
• Environmental regulatory compliance meeting RoHS 3 and REACH requirements for safe industrial use

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these 316 stainless steel rounded head slotted screws deliver exceptional performance where corrosion resistance is critical. The passivated finish enhances the natural corrosion-fighting properties of 316 stainless steel, making these UNC threaded fasteners ideal for marine applications, chemical processing equipment, food processing machinery, and outdoor installations. The coarse thread spacing and Class 2A thread fit provide excellent engagement in various materials while resisting loosening under vibration. The rounded head profile distributes clamping force evenly, while the slotted drive offers reliable installation with standard tools. These fully threaded screws maintain consistent holding power throughout their length, ensuring secure fastening in critical assemblies where reliability cannot be compromised.

Specification Summary & Compliance

This 4-40 UNC 1/2" screw features precise Class 2A thread fit tolerances and right-hand threading with coarse spacing. Manufactured to ASME B18.6.3 dimensional standards for guaranteed interchangeability. The fastener meets RoHS 3 (2015/863/EU) compliance for restricted substances and REACH (EC 1907/2006) regulations for chemical safety. Mechanical properties include Rockwell B100 hardness and 100,000 psi tensile strength, ensuring reliable performance in industrial applications requiring corrosion-resistant fastening solutions.