S-91781A106 4-40 x 1/4" 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 load-bearing performance
- Precision thread engagement with Class 2A fit and UNC coarse threads ensuring secure fastening and vibration resistance
- Optimal flush mounting with standard 82° countersink angle and flat head design for smooth surface integration
- Broad compatibility with ASME B18.6.3 standards, meeting rigorous engineering specifications
- Enhanced durability through full threading and right-hand thread direction for consistent installation strength
- Regulatory compliance with RoHS 3 and REACH, ensuring safe use in regulated industries
Professional Applications & Engineering Value
These 4-40 UNC flat head slotted screws deliver critical performance in demanding applications where material integrity and precision are paramount. The 18-8 stainless steel base, enhanced by a passivated finish, provides excellent resistance to oxidation and chemical exposure, extending service life in machinery, electronics, and outdoor equipment. The coarse UNC threading and Class 2A thread fit facilitate quick assembly while maintaining high clamp load, reducing the risk of loosening under dynamic stresses. With an 82° countersink angle and flat head profile, these screws sit flush with surfaces, preventing snagging and improving aesthetics in consumer products and industrial enclosures. Fully threaded for maximum grip, they are a go-to industrial fastener for OEMs and maintenance teams requiring reliable, standards-compliant solutions.
Specification Summary & Compliance
This product adheres to ASME B18.6.3 specifications, with precise dimensional controls including a Class 2A thread fit for consistent interchangeability. Threading follows UNC coarse standards with a 4-40 size, 1/4" length, and right-hand direction. Manufacturing complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions are met for global supply chain integration.
