S-91255A078 2-56 x 5/16" 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
- Exceptional tensile strength (120,000 psi) ensures reliable performance in high-stress industrial applications
- Superior corrosion resistance through black-oxide coating extends service life in demanding environments
- Precision Class 3A thread fit provides secure, vibration-resistant connections with minimal play
- Hex drive design (0.050") enables efficient installation with standard tools, reducing assembly time
- Rounded button head profile offers a low-profile, aesthetically clean finish while preventing snagging
- Coarse UNC threading ensures quick engagement and superior holding power in various materials
- Full compliance with industry standards guarantees consistent quality and regulatory acceptance
Professional Applications & Engineering Value
These black-oxide alloy steel rounded head screws deliver exceptional engineering value across multiple industrial sectors. The combination of Rockwell C39 hardness and 120,000 psi tensile strength makes them ideal for applications requiring reliable fastening under mechanical stress, including precision equipment assemblies, electronic enclosures, and machinery components. The 2-56 UNC coarse threading provides rapid installation while maintaining secure connections in materials where fine threads might strip. The hex drive configuration ensures positive torque transmission without cam-out, while the black-oxide surface treatment offers substantial corrosion protection for extended service life in challenging environments. These fully threaded fasteners with Class 3A fit maintain dimensional consistency for predictable performance in automated assembly processes.
Specification Summary & Compliance
This precision fastener features 2-56 UNC coarse threading with Class 3A thread fit for superior dimensional accuracy. Manufacturing complies with ASME B18.3 and ASTM F835 specifications, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting the latest industry standards for hazardous substance restrictions and chemical safety.
