S-91253A581 5/16"-18 x 3/4" ASME B18.3 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 coating for extended service life in demanding industrial environments
- Exceptional mechanical strength with 130,000 psi tensile strength and Rockwell C39 hardness for heavy-duty applications
- Precise Class 3A thread fit ensures reliable engagement and vibration resistance in critical assemblies
- Optimized installation efficiency with 3/16" hex drive design providing superior torque transmission
- Perfect flush mounting achieved through 82° countersink angle and standard flat head profile
- Enhanced thread engagement with coarse UNC threading for faster assembly in various materials
- Full regulatory compliance meeting international standards for quality and environmental safety
Professional Applications & Engineering Value
These black-oxide alloy steel flat head screws deliver exceptional performance in industrial fastening applications where reliability and durability are paramount. The combination of 130,000 psi tensile strength and Rockwell C39 hardness ensures these hex drive screws withstand extreme mechanical stresses without compromising integrity. The 5/16"-18 UNC coarse threading provides superior grip in various substrates, while the 82° countersink angle creates seamless flush mounting in precision assemblies. Engineered with Class 3A thread fit, these fully threaded screws maintain consistent clamping force in high-vibration environments, making them ideal for machinery, equipment manufacturing, and structural applications requiring heavy-duty fastening solutions.
Specification Summary & Compliance
Manufactured to exacting inch system dimensions with Class 3A thread fit precision and UNC coarse threading specifications. These flat head screws strictly adhere to ASME B18.3 and ASTM F835 manufacturing standards, ensuring dimensional accuracy and mechanical performance. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, providing assurance for international industrial applications requiring certified heavy-duty fasteners.
