S-91253A125 5-40 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
- Exceptional corrosion resistance with black-oxide coating on alloy steel, ideal for harsh industrial environments
- Superior load-bearing capacity from 130,000 psi tensile strength and Rockwell C39 hardness for reliable performance
- Precise flush mounting enabled by the 82° countersink angle and flat head design for seamless surface integration
- Optimized installation efficiency with hex drive (5/64") ensuring secure tool engagement and reduced slippage
- Consistent threading performance through Class 3A thread fit and UNC coarse threads for vibration resistance
- Full-length thread coverage allowing maximum grip and adjustment flexibility in assemblies
- Compliance with global standards including ASTM F835, RoHS 3, and REACH for assured quality and safety
Professional Applications & Engineering Value
These 5-40 UNC flat head screws deliver critical reliability in demanding applications where material integrity and precision are paramount. The black-oxide alloy steel construction resists oxidation and wear, extending service life in machinery, automotive, and electrical enclosures. The fully threaded design and coarse thread spacing enhance grip in softer materials or where vibration loosening is a concern. With a hex drive and standard flat head profile, they enable rapid, flush installations without protrusions—ideal for aerospace components, industrial controls, and assembly lines requiring repeatable, high-strength fastening solutions that meet rigorous ASTM F835 specifications.
Specification Summary & Compliance
This screw adheres to Class 3A thread fit for tight tolerances and UNC coarse threading (5-40 size) with right-hand orientation. Dimensions include 5/16" length, 0.281" head diameter, and 5/64" hex drive. It conforms to ASTM F835 manufacturing standards and is verified as RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, ensuring environmental safety and material traceability.
