S-91255A618 3/8"-16 x 4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance in demanding applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides consistent, secure fastening with reduced risk of cross-threading or loosening under vibration.
• High hardness (Rockwell C39) offers excellent wear resistance, maintaining thread integrity through repeated installations.
• Fully threaded UNC coarse spacing allows for faster installation and stronger holding power in a wide range of materials.
• Hex drive design (7/32") enables high-torque application with standard tools, speeding up assembly processes.
• Rounded button head profile provides a low-profile, aesthetically clean finish while reducing snagging hazards.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these black-oxide alloy steel screws deliver outstanding performance in machinery assembly, structural frameworks, and equipment manufacturing. The combination of Class 3A thread fit and UNC coarse threading ensures rapid installation with superior resistance to vibrational loosening—critical in dynamic operating environments. The fully threaded design maximizes engagement depth across various material thicknesses, while the 120,000 psi tensile strength provides a safety margin for high-stress connections. The corrosion-resistant black-oxide surface treatment protects against degradation in humid or chemically exposed settings, making these hex drive rounded head screws ideal for automotive, construction, and industrial maintenance applications where reliability and durability are paramount.

Specification Summary & Compliance

This 3/8"-16 x 4" rounded head screw features precision UNC coarse threads with Class 3A fit for exacting dimensional accuracy. Manufactured to meet ASME B18.3 and ASTM F835 specifications, ensuring consistent quality and performance. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, guaranteeing safe use in regulated industries.