S-91309A640 3/8"-16 x 4" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating that extends service life in demanding industrial environments
• High tensile strength of 60,000 psi ensures reliable performance under heavy loads and vibration
• Rockwell B69 hardness provides excellent durability and resistance to deformation during installation
• Class 2A thread fit offers optimal assembly clearance while maintaining secure fastening integrity
• Full threading along the 4" length enables maximum grip and adjustment flexibility in various material thicknesses
• External hex drive design allows for high-torque installation with standard tools and easy maintenance access
• Compliance with major industry standards including ASME B18.2.1, RoHS 3, and REACH for guaranteed quality and environmental safety

Professional Applications & Engineering Value

These 3/8"-16 UNC coarse thread hex head screws deliver exceptional engineering value across industrial applications where vibration resistance and long-term reliability are critical. The zinc plated steel construction provides essential corrosion protection for outdoor equipment, machinery frames, and structural assemblies exposed to moisture or chemical environments. The coarse UNC thread profile ensures rapid installation and superior holding power in softer materials like aluminum or wood composites, while the external hex drive enables high-torque tightening without cam-out issues. With full threading along the entire 4" length, these fasteners accommodate varying material thicknesses in construction, manufacturing, and heavy equipment applications where consistent clamping force is paramount to structural integrity.

Specification Summary & Compliance

Manufactured to precise Class 2A thread fit tolerances with UNC coarse thread specifications (3/8"-16 thread size), these hex head screws guarantee consistent performance and interchangeability. The product strictly adheres to ASME B18.2.1 dimensional standards and ASTM A307 material specifications, ensuring mechanical properties meet industrial requirements. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) certifications, confirming the absence of restricted substances for global market acceptance. The combination of 60,000 psi tensile strength and Rockwell B69 hardness provides documented performance metrics for engineering calculations and safety-critical applications.