S-91255A021 4-40 x 7/16" ASTM F835 Steel Button Head Hex-Drive Screws
Steel Button Head Hex-Drive 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 black-oxide coating that protects against rust and extends service life in demanding environments
- Exceptional mechanical strength with 120,000 psi tensile strength and Rockwell C39 hardness for reliable performance under high stress
- Precise Class 3A thread fit ensures tight, secure fastening with minimal risk of loosening in critical assemblies
- Easy installation and removal with 1/16" hex drive design providing superior torque transmission and reduced tool slippage
- Full threading along the 7/16" length offers maximum grip and uniform load distribution across the entire fastener
- Broad industrial compliance meeting ASME B18.3 and ASTM F835 standards for guaranteed dimensional accuracy and performance
- Environmentally responsible manufacturing with RoHS 3 and REACH compliance for safe use in regulated industries
Professional Applications & Engineering Value
Engineered for precision-critical applications, these 4-40 UNC coarse thread screws with rounded button head design provide optimal performance in electronic enclosures, machinery assemblies, and automotive components. The black-oxide alloy steel construction delivers enhanced corrosion protection where moisture or chemicals are present, while the Class 3A thread fit maintains tight tolerances in vibration-prone environments. The 1/16" hex drive enables high-torque installation without stripping, and the fully threaded 7/16" length ensures consistent clamping force across the entire engagement area. These industrial-grade fasteners solve common challenges of thread stripping, corrosion failure, and installation inefficiency in production lines and maintenance operations.
Specification Summary & Compliance
This fastener maintains Class 3A thread fit per UNC standards with coarse thread spacing for rapid assembly. Manufacturing complies with ASME B18.3 for dimensional consistency and ASTM F835 for material properties. The product is certified RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental regulations for hazardous substance restrictions.
