S-90429A143 3/4"-16 x 1 1/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 PSI ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life in demanding industrial environments.
• Precise Class 3A thread fit provides secure, vibration-resistant connections, minimizing loosening in machinery and equipment.
• Fully threaded design allows for maximum grip and uniform load distribution along the entire length.
• Hex drive compatibility with a 1/2" drive size enables easy installation and removal using standard tools, saving time on assembly lines.
• High hardness rating of Rockwell C37 enhances wear resistance, maintaining thread integrity through repeated use.
• Compliance with major standards including ASME B18.3 and ASTM F835, ensuring consistency and safety in regulated industries.

Professional Applications & Engineering Value

This 3/4"-16 UNF flat head socket cap screw is engineered to address critical challenges in heavy-duty assembly, such as vibration-induced loosening and material fatigue. The black-oxide alloy steel construction, combined with a fine thread spacing and Class 3A precision, delivers a tight, reliable fit that withstands dynamic loads in machinery, automotive, and construction applications. Its fully threaded right-hand design ensures maximum engagement in tapped holes, reducing stress concentration points. The flat head profile allows for flush mounting, ideal for spaces where protrusions are not feasible, while the hex drive facilitates quick installation with common tools, enhancing efficiency in production environments.

Specification Summary & Compliance

This screw features a 3/4"-16 UNF thread with Class 3A fit for high precision and fine thread spacing, ensuring accurate alignment in assemblies. It meets ASME B18.3 and ASTM F835 specifications for dimensional consistency and performance. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally conscious and regulated industries without hazardous substances.