S-90585A042 1/4"-20 x 1 5/8" 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 for extended service life in harsh environments
• Precise countersinking capability with 82° flat head profile for flush mounting in demanding applications
• Maximum thread engagement through fully threaded design and Class 3A fit for superior holding power
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness for heavy-duty applications
• Secure installation with hex drive design providing positive torque transmission and reduced cam-out risk
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations including RoHS 3 and REACH
• Optimized for industrial use with coarse UNC threading for faster installation and reduced cross-threading in challenging conditions

Professional Applications & Engineering Value

These 316 stainless steel flat head screws with 1/4"-20 UNC coarse threading deliver exceptional engineering value in corrosive and high-stress environments. The combination of passivated finish and marine-grade stainless steel provides superior protection against chemical exposure, saltwater, and industrial contaminants, significantly reducing maintenance costs and downtime. The fully threaded design ensures maximum grip length and load distribution, while the 82° countersink angle creates seamless flush mounting in precision machinery, marine equipment, and chemical processing applications. The hex drive system allows for high-torque installation without slippage, making these fasteners ideal for assembly lines and maintenance operations where reliability and corrosion resistance are critical performance factors.

Specification Summary & Compliance

Manufactured to exacting ASME B18.3 standards with Class 3A thread fit for superior dimensional accuracy and consistent performance. These inch-system fasteners feature precise UNC coarse threading (1/4"-20) and maintain full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The mechanical properties include 70,000 psi tensile strength and Rockwell B55 hardness, ensuring reliable performance in industrial applications requiring durable, corrosion-resistant fastening solutions.