S-91781A112 4-40 x 5/8" 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 and passivated finish, ideal for harsh environments
- High tensile strength of 80,000 psi ensures reliable, long-lasting fastening under demanding loads
- Rockwell B80 hardness provides excellent durability and resistance to wear and deformation
- Class 2A thread fit with UNC coarse threading offers easy assembly and secure engagement in various materials
- Standard 82° countersink angle and flat head design allows for flush mounting and a clean, professional appearance
- Full compliance with ASME B18.6.3 guarantees precise dimensional accuracy and interchangeability
- RoHS 3 and REACH compliant ensures environmental safety and regulatory adherence for global supply chains
Professional Applications & Engineering Value
These 4-40 UNC flat head slotted screws in 18-8 stainless steel are engineered to address critical industrial challenges, such as corrosion in moist or chemical-exposed settings. The passivated finish enhances surface protection, reducing the risk of rust and extending service life in applications like machinery assembly, electronic enclosures, and automotive components. With a coarse thread and Class 2A fit, they provide quick installation and strong holding power in softer materials or where vibration resistance is key. The flat head design with an 82° countersink ensures a smooth, flush fit, minimizing protrusions in precision equipment. Ideal for B2B procurement, these screws deliver consistent performance, meeting rigorous standards for industrial fasteners that require both strength and compliance.
Specification Summary & Compliance
This product adheres to Class 2A thread fit and UNC coarse thread standards, ensuring precise dimensional tolerances per ASME B18.6.3. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming environmental safety and material restrictions. The specifications include a right-hand thread, fully threaded design, and standard flat head profile for reliable fastening in industrial applications.
