S-90317A179 M4 x 25 mm ASME B18.13.1M Stainless Steel Pan Head Phillips Screws with Internal-Tooth Lock Washer

Key Features & Benefits at a Glance

• Superior vibration resistance with integrated internal-tooth lock washer that maintains secure fastening in high-motion environments
• Excellent corrosion protection through passivated 18-8 stainless steel construction for extended service life in harsh conditions
• Reliable thread engagement with Class 6g metric coarse threads ensuring consistent performance and easy installation
• High mechanical strength offering 70,000 psi tensile strength and Rockwell B70 hardness for demanding industrial applications
• Optimized drive efficiency with Phillips No. 2 drive providing secure tool engagement and reduced cam-out risk
• Enhanced locking performance through 410 stainless steel washer material that maintains its locking properties under stress
• Full thread coverage along the 25mm length for maximum grip strength and load distribution

Professional Applications & Engineering Value

These M4 pan head screws with internal-tooth lock washers deliver critical vibration resistance in industrial machinery, automotive assemblies, and electronic enclosures where loosening under dynamic loads is a primary concern. The 18-8 stainless steel core material combined with passivated finish provides exceptional corrosion resistance against moisture, chemicals, and environmental exposure, significantly extending maintenance intervals. The metric coarse threading with Class 6g tolerance ensures reliable engagement in both metallic and composite materials, while the integrated lock washer eliminates the need for separate locking components, streamlining assembly processes. These fully threaded screws maintain consistent clamping force across the entire 25mm length, making them ideal for applications requiring uniform stress distribution and reliable fastening integrity.

Specification Summary & Compliance

Manufactured to ASME B18.13.1M specifications with Class 6g thread fit tolerance for precision metric fastening. The complete assembly features M4 x 0.7mm coarse threads with 25mm fully threaded length and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance standards for environmental safety. The passivated finish on both screw and washer components ensures consistent corrosion protection while maintaining dimensional stability across industrial applications.