S-94688A331 1/2"-13 x 4" ASME B18.2.1 Square Head Screws

Key Features & Benefits at a Glance

• Maximum Load Capacity - SAE Grade 8 classification with 150,000 psi tensile strength ensures reliable performance under extreme mechanical stress
• Superior Corrosion Protection - Zinc yellow-chromate plating provides enhanced rust resistance for extended service life in harsh environments
• Optimized Thread Engagement - 1/2"-13 UNC coarse thread design delivers superior holding power and faster installation in structural applications
• Precision Thread Quality - Class 3A thread fit guarantees consistent mating with nuts and threaded components for secure fastening
• Enhanced Torque Application - External square drive head design allows for high-torque installation using standard wrenches
• Industry Standard Compliance - Manufactured to ASME B18.2.1 specifications ensuring dimensional accuracy and interchangeability
• Full Thread Coverage - 4" length with complete threading provides maximum grip length for critical connections

Professional Applications & Engineering Value

This heavy-duty square head screw addresses critical engineering challenges in industrial applications where vibration resistance and structural integrity are paramount. The SAE Grade 8 steel construction with 150,000 psi tensile strength provides exceptional resistance to mechanical fatigue and shock loading, making it ideal for heavy machinery, structural steel connections, and construction equipment. The 1/2"-13 UNC coarse thread configuration ensures rapid assembly while maintaining superior clamping force, particularly beneficial in wood-to-metal and structural steel applications. The zinc yellow-chromate plating offers reliable corrosion protection in environments exposed to moisture and industrial chemicals, significantly extending service life and reducing maintenance frequency. The external square drive design facilitates high-torque installation without cam-out issues, ensuring secure fastening in high-vibration industrial settings.

Specification Summary & Compliance

This square head screw features precise Class 3A thread fit per Unified Standard specifications, ensuring optimal engagement with mating components. The fastener maintains dimensional compliance with ASME B18.2.1 manufacturing standards, guaranteeing interchangeability and reliability across industrial applications. The 1/2"-13 UNC coarse thread with right-hand orientation provides standardized threading compatible with industry-standard nuts and threaded holes. The product meets RoHS and REACH environmental compliance requirements while delivering consistent performance across temperature variations and mechanical stress conditions.