S-91781A105 4-40 x 3/16" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws
Stainless Steel Slotted Flat Head Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh industrial environments
- Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable, long-lasting fastening
- Optimal flush mounting featuring an undercut flat head design that sits perfectly countersunk in 82° angle applications
- Easy manual installation with standard slotted drive style for straightforward assembly using common tools
- Precise thread engagement with Class 2A thread fit and UNC coarse threading ensuring secure connections in various materials
- Full-threaded design provides maximum grip length and holding power across the entire 3/16" fastener length
- Regulatory compliance meets ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH
Professional Applications & Engineering Value
These 4-40 UNC flat head slotted screws deliver critical performance advantages in demanding industrial applications where corrosion resistance and precise flush mounting are essential. The combination of 18-8 stainless steel material with passivated finish provides exceptional protection against oxidation and chemical exposure, making them ideal for electronics enclosures, machinery components, and marine equipment. The undercut flat head profile ensures proper seating in countersunk holes without protrusion, while the coarse thread spacing and Class 2A thread fit maintain secure fastening in softer materials and vibration-prone environments. With full threading along the entire 3/16" length, these screws maximize engagement depth for superior pull-out resistance in critical assemblies.
Specification Summary & Compliance
This fastener maintains precise Class 2A thread fit tolerances with UNC coarse thread specifications (4-40 size) and features an 82° countersink angle for standard flat head applications. Manufacturing and dimensional compliance strictly adhere to ASME B18.6.3 standards, ensuring interchangeability and reliability across industrial applications. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted substances for global market acceptance.
