S-90402A839 10-32 x 1 1/4" ASME B18.13 Steel Pan Head Phillips Screws with External-Tooth Lock Washer

Key Features & Benefits at a Glance

• Superior vibration resistance with integrated external-tooth lock washer that maintains secure fastening in high-motion environments
• Enhanced corrosion protection through zinc-plated steel construction for extended service life in industrial conditions
• Optimized drive engagement with Phillips No. 2 drive design providing reliable torque transmission and reduced cam-out risk
• Precision thread performance featuring Class 2A UNF fine threads ensuring consistent fit and superior holding power
• High mechanical strength delivering 60,000 psi tensile strength and Rockwell B69 hardness for demanding applications
• Full-threaded design maximizing grip length and distribution of clamping force across the entire fastener
• Regulatory compliance assurance meeting ASME B18.13 standards while being RoHS 3 and REACH compliant

Professional Applications & Engineering Value

These 10-32 UNF screws with zinc-plated steel construction address critical industrial fastening challenges where vibration loosening and environmental exposure compromise joint integrity. The combination of fine UNF threads and external-tooth lock washers creates a mechanical locking system that resists back-off under dynamic loads, making them ideal for machinery, equipment assembly, and automotive applications. The pan head profile with Phillips drive provides both adequate bearing surface and efficient installation, while the Class 2A thread fit ensures consistent engagement without binding. This engineered solution delivers reliable performance in environments where maintenance access is limited and fastener failure is not an option.

Specification Summary & Compliance

This 1 1/4" length screw features precision Class 2A thread fit with UNF fine thread specification (10-32) and right-hand threading. Manufactured to ASME B18.13 standards, the fastener demonstrates full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The external-tooth lock washer (0.383" OD, 0.024" thickness) is integrally assembled to the zinc-plated steel screw, creating a complete vibration-resistant fastening system ready for industrial deployment.