S-91263A136 4-40 x 5/16" ASTM F835 Alloy Steel Hex Drive Flat Head Screws
Alloy Steel Hex Drive 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 zinc-plated alloy steel construction for extended service life in demanding environments
- Precise flush mounting achieved through standard 82° countersink angle and flat head design for clean, professional finishes
- Maximum thread engagement reliability with Class 3A thread fit ensuring tight, secure fastening in critical applications
- Exceptional mechanical strength delivering 130,000 psi tensile strength and Rockwell C39 hardness for heavy-duty performance
- Optimized drive efficiency through hex drive design providing superior torque transmission and reduced cam-out risk
- Full-threaded versatility offering consistent holding power across the entire screw length for various material thicknesses
- Industry compliance assurance meeting ASME B18.3, ASTM F835, RoHS 3, and REACH standards for quality and safety
Professional Applications & Engineering Value
These 4-40 UNC flat head screws with zinc-plated alloy steel construction address critical engineering challenges in industrial fastening. The Class 3A thread fit provides exceptional precision for applications requiring vibration resistance and reliable seating in metal assemblies, electronics enclosures, and machinery components. The fully threaded design ensures consistent clamping force distribution, while the 82° countersink angle enables seamless flush installation in precision equipment. With coarse thread spacing and right-hand thread direction, these screws offer quick assembly and disassembly in maintenance-intensive environments. The hex drive configuration prevents stripping during high-torque installation, making them ideal for automotive, aerospace, and industrial manufacturing applications where fastener integrity is paramount.
Specification Summary & Compliance
Manufactured to exacting inch system dimensions with 5/16" length and Class 3A thread fit precision. Complies with ASME B18.3 and ASTM F835 specifications for dimensional accuracy and mechanical properties. Features UNC thread type with coarse thread spacing for optimal performance in various materials. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance standards for environmental safety and regulatory requirements.
