S-94688A330 1/2"-13 x 3 1/2" ASME B18.2.1 Square Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength with 150,000 psi rating ensures reliable performance in high-stress applications
• Superior corrosion resistance provided by zinc yellow-chromate plating for extended service life in harsh environments
• Optimal thread engagement through 1/2"-13 UNC coarse thread design delivers superior holding power and faster installation
• Enhanced torque capability from the external square drive head allows for secure tightening without stripping
• Precision thread fit with Unified Standard Class 3A ensures consistent performance and reliable fastening
• Full threading design provides maximum grip length and versatile application across various material thicknesses
• Industry compliance with ASME B18.2.1 specifications guarantees quality and reliability for professional use

Professional Applications & Engineering Value

This SAE Grade 8 square head screw delivers exceptional engineering value for demanding industrial applications where vibration resistance and structural integrity are paramount. The 1/2"-13 UNC coarse thread configuration provides superior pull-out resistance in materials like steel, aluminum, and heavy timber, while the external square drive design prevents cam-out during high-torque installation. The zinc yellow-chromate plating offers enhanced corrosion protection, making it ideal for outdoor equipment, construction machinery, and industrial assembly lines exposed to moisture and harsh conditions. With fully threaded construction and Class 3A thread fit, this fastener ensures maximum engagement strength and reliable performance in critical connections where failure is not an option.

Specification Summary & Compliance

This heavy-duty fastener features precise 1/2"-13 UNC coarse threads with Unified Standard Class 3A fit for optimal engagement and consistent performance. Manufactured from high-strength steel and finished with zinc yellow-chromate plating for corrosion resistance, the screw meets ASME B18.2.1 specifications for dimensional accuracy and quality assurance. The 3 1/2" length with full threading provides versatile application capabilities, while the SAE Grade 8 classification guarantees the 150,000 psi tensile strength rating for demanding industrial applications requiring reliable fastening solutions.