S-99926A146 5/16"-18 x 5/8" Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance from 18-8 stainless steel and passivated finish for extended service life in harsh environments
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B70 hardness for heavy-duty applications
• Precise thread engagement with Class 3A thread fit ensuring reliable, vibration-resistant connections
• Optimal flush mounting featuring 100° countersink angle and undercut head design for seamless surface integration
• Enhanced installation efficiency with hex drive style providing secure tool engagement and torque transmission
• Reduced cross-threading risk through UNC coarse thread spacing for faster assembly in industrial settings
• Regulatory compliance assurance meeting RoHS 3 and REACH standards for global supply chain compatibility

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws deliver critical performance advantages in demanding industrial environments. The 18-8 stainless steel construction combined with passivated finish provides exceptional resistance to corrosion and chemical exposure, making them ideal for machinery, marine equipment, and food processing applications where moisture resistance is paramount. The Class 3A thread fit ensures precise tolerance control, minimizing vibration-induced loosening in dynamic load conditions. The undercut flat head profile with 100° countersink angle allows for perfect flush mounting in precision-machined components, while the hex drive design enables high-torque installation without cam-out issues. These partially threaded screws offer optimal clamping force distribution, making them particularly valuable in assembly operations requiring both secure fastening and alignment accuracy.

Specification Summary & Compliance

Manufactured to inch system standards with Class 3A thread fit precision and UNC coarse thread spacing. Features include 5/16"-18 thread size, 5/8" length, partial threading with minimum 0.44" thread length, and 100° countersink angle. Mechanical properties include 70,000 psi tensile strength and Rockwell B70 hardness. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for industrial applications with strict material restrictions.