S-90276A599 5/16"-18 x 4" ASME B18.6.3 Steel Round Head Slotted Screws

Key Features & Benefits at a Glance

• Enhanced Corrosion Resistance: Zinc-plated steel construction provides reliable protection against rust, extending service life in demanding industrial environments.
• Superior Tensile Strength: With a 60,000 psi tensile strength and Rockwell B69 hardness, this screw offers exceptional durability and resistance to shear forces.
• Optimized Thread Engagement: Coarse UNC threads and Class 2A fit ensure quick assembly and secure fastening, reducing installation time and improving joint reliability.
• Versatile Partial Threading: The partially threaded design allows for effective clamping of materials, preventing loosening under vibration and dynamic loads.
• Broad Regulatory Compliance: Meets ASME B18.6.3 specifications and is RoHS 3 & REACH compliant, ensuring safety and environmental standards for global supply chains.
• User-Friendly Installation: Slotted drive and rounded head profile facilitate easy driving with standard tools, minimizing the risk of cam-out and tool wear.
• Precision Dimensional Consistency: Standardized 4" length and 0.59" head diameter guarantee reliable fit and interchangeability in repetitive assembly operations.

Professional Applications & Engineering Value

This 5/16"-18 UNC zinc-plated steel rounded head screw is engineered to address critical fastening challenges in industrial settings. The coarse thread design and partial threading enhance grip strength in soft materials and wood, reducing the risk of strip-out while maintaining clamp load under vibration. The zinc plating offers a cost-effective barrier against oxidation, making it ideal for outdoor equipment, electrical enclosures, and machinery subjected to humid conditions. With a 60,000 psi tensile strength, it reliably secures structural components in automotive, construction, and HVAC systems, where ASME B18.6.3 compliance ensures consistent performance and safety. The slotted drive and rounded head allow for quick maintenance and disassembly, streamlining operations in high-volume production lines.

Specification Summary & Compliance

This screw adheres to Class 2A thread fit tolerances per UNC standards, ensuring precise engagement and interchangeability. It conforms to ASME B18.6.3 manufacturing specifications for dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing the absence of restricted hazardous substances for safe use in industrial and consumer applications.