S-90585A081 1"-8 x 2 1/2" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction and passivated finish, ideal for harsh industrial environments
• High-strength performance delivering 70,000 psi tensile strength and Rockwell B55 hardness for demanding applications
• Precision thread engagement with Class 3A fit and UNC coarse spacing ensuring reliable fastening in various materials
• Optimal flush mounting with standard 82° countersink angle and flat head design for clean, secure installations
• Enhanced torque transmission through 5/8" hex drive design for secure installation and removal
• Full threading coverage along the 2½" length provides maximum grip and load distribution
• Regulatory compliance assurance meeting ASME B18.3 standards and RoHS/REACH environmental requirements

Professional Applications & Engineering Value

These 316 stainless steel flat head screws with 1"-8 UNC coarse threading are engineered to address critical industrial fastening challenges where corrosion resistance and structural integrity are paramount. The passivated finish significantly enhances the natural corrosion resistance of 316 stainless steel, making these hex drive screws ideal for marine, chemical processing, and outdoor applications exposed to moisture and aggressive chemicals. The Class 3A thread fit ensures precise engagement in tapped holes, reducing the risk of cross-threading while maintaining vibration resistance in high-stress environments. The combination of 70,000 psi tensile strength and fully threaded design provides exceptional clamping force distribution across the entire fastener length, making them particularly valuable in structural assemblies, heavy machinery, and equipment requiring reliable, long-term fastening solutions.

Specification Summary & Compliance

Manufactured to exacting dimensional standards with Class 3A thread fit and UNC coarse thread spacing, these screws maintain precision tolerances for head diameter and profile. The product fully complies with ASME B18.3 specifications for dimensional requirements and mechanical properties. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) certifications, ensuring adherence to current environmental regulations for hazardous substance restrictions.