S-91771A934 4-40 x 1/4" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws
Stainless Steel Phillips 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 passivated 18-8 stainless steel construction, ensuring long-term reliability in harsh environments.
- Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for secure, high-stress fastening applications.
- Precise thread engagement through Class 2A thread fit and UNC coarse threading, providing reliable installation and vibration resistance.
- Streamlined flush mounting with a standard flat head profile and 100° countersink angle for seamless, professional-looking assemblies.
- Efficient installation and removal using the Phillips No. 1 drive, reducing assembly time and tool slippage.
- Full-threaded design ensures maximum grip and load distribution along the entire 1/4" length for enhanced joint integrity.
- Compliance with major industry standards including ASME B18.6.3, RoHS 3, and REACH, guaranteeing safety and regulatory adherence.
Professional Applications & Engineering Value
These 4-40 UNC flat head screws are engineered to address critical industrial fastening challenges, such as corrosion, vibration loosening, and high tensile demands. The passivated 18-8 stainless steel material offers excellent resistance to oxidation and chemical exposure, making them ideal for electronics, machinery, and outdoor equipment. The combination of coarse threading and Class 2A thread fit ensures quick, secure installation with minimal cross-threading risk, while the flat head with 100° countersink allows for a smooth, flush finish in pre-drilled holes. With a Phillips No. 1 drive, these screws facilitate efficient assembly in confined spaces, enhancing productivity in automated or manual manufacturing processes.
Specification Summary & Compliance
This product adheres to precise dimensional standards, including Class 2A thread fit for consistent engagement and UNC coarse thread specifications. Manufacturing and quality are governed by ASME B18.6.3, ensuring reliability across industrial applications. Additionally, these screws are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming they are free from hazardous substances and safe for global use.
