S-90317A590 M4 x 25 mm ASME B18.13.1M Stainless Steel Pan Head Phillips Screws with External-Tooth Lock Washer

Key Features & Benefits at a Glance

• Superior vibration resistance through integrated external-tooth lock washer that maintains clamping force in high-stress environments
• Excellent corrosion protection with passivated 18-8 stainless steel construction for extended service life in harsh conditions
• Reliable fastening performance with Class 6g thread fit ensuring precise engagement and consistent torque values
• High mechanical strength offering 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Quick installation efficiency with Phillips No. 2 drive and coarse thread pitch enabling rapid assembly
• Secure locking action from the 410 stainless steel washer that prevents loosening under dynamic loads
• Full thread engagement along the entire 25mm length for maximum holding power across the fastened joint

Professional Applications & Engineering Value

These M4 metric screws with external-tooth lock washer provide critical vibration-resistant fastening solutions for industrial equipment, machinery, and automotive assemblies. The 18-8 stainless steel construction with passivated finish ensures reliable performance in corrosive environments where carbon steel fasteners would fail. The combination of fully threaded design and coarse thread pitch enables quick installation while maintaining high pull-out strength. The pan head Phillips drive offers familiar tooling compatibility for maintenance crews, reducing installation time and tooling costs. Engineered to prevent costly downtime from fastener failure, these screws deliver consistent clamping force in applications subject to thermal cycling, mechanical vibration, and dynamic loading conditions.

Specification Summary & Compliance

This M4 x 0.7mm pitch x 25mm length screw features Class 6g thread fit tolerance per metric standards and fully threaded design for maximum engagement. Manufacturing complies with ASME B18.13.1M specifications for dimensional accuracy and performance. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) standards for chemical safety. Both screw and washer components feature passivated finish for enhanced corrosion resistance while maintaining the mechanical properties of 18-8 stainless steel and 410 stainless steel respectively.