S-91253A301 1/4"-28 x 3/8" 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 black-oxide finish, extending service life in demanding industrial environments
- Exceptional tensile strength of 130,000 psi ensures reliable performance under high-stress applications
- Precision Class 3A thread fit provides superior engagement and vibration resistance in critical assemblies
- Optimized flush mounting with 82° countersink angle and flat head design for seamless surface integration
- Enhanced torque transmission through 5/32" hex drive socket, preventing tool slippage during installation
- Full threading along 3/8" length enables maximum grip and uniform load distribution
- Industry compliance assurance meeting ASME B18.3 and ASTM F835 specifications for guaranteed quality
Professional Applications & Engineering Value
This black-oxide alloy steel flat head socket cap screw delivers critical performance advantages in precision machinery, automotive systems, and industrial equipment where vibration resistance and flush surface requirements are paramount. The UNF fine thread configuration with Class 3A fit ensures superior clamping force retention in high-vibration environments, while the 82° countersink angle provides optimal seating in chamfered holes. Engineered with 130,000 psi tensile strength and Rockwell C39 hardness, this fastener maintains structural integrity under extreme loads, making it ideal for critical assemblies requiring reliable, long-term performance without surface protrusion interference.
Specification Summary & Compliance
Manufactured to exacting Class 3A thread tolerances per UNF standards with 1/4"-28 fine thread specification. Complies with ASME B18.3 dimensional requirements and ASTM F835 material specifications. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards. Features right-hand thread direction and fully threaded design across the 3/8" length with standard flat head profile and 5/32" hex drive configuration.
