S-91771A975 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, ideal for harsh industrial environments
- Exceptional mechanical strength with 80,000 PSI tensile strength and Rockwell B80 hardness for reliable load-bearing performance
- Precise thread engagement with Class 2A fit and UNC coarse threads ensuring secure fastening and vibration resistance
- Optimized flush mounting featuring undercut flat head design and 100° countersink angle for seamless surface integration
- Industry-compliant manufacturing meeting ASME B18.6.3 standards for dimensional accuracy and interchangeability
- Enhanced drive stability with Phillips No. 1 drive providing consistent torque transmission and reduced cam-out risk
- Environmental compliance assurance with RoHS 3 and REACH regulations for safe use in regulated applications
Professional Applications & Engineering Value
These 4-40 UNC flat head screws deliver critical engineering solutions where corrosion resistance and high tensile strength are paramount. The passivated 18-8 stainless steel material provides excellent protection against oxidation and chemical exposure, making these Phillips machine screws ideal for electronics enclosures, machinery panels, and automotive assemblies. The undercut flat head profile and 100° countersink angle ensure flush mounting without protrusion, while the coarse UNC threads enable rapid installation in soft materials and prevent cross-threading. With full threading and Class 2A fit, these industrial fasteners maintain consistent clamping force in high-vibration environments, addressing common loosening issues in dynamic applications.
Specification Summary & Compliance
This 1/4" length screw maintains precise Class 2A thread fit per UNC standards with right-hand threading. Manufacturing conforms to ASME B18.6.3 specifications for dimensional accuracy. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and regulatory acceptance for global industrial applications.
