S-93996A125 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with permanent nylon patch thread locker that maintains secure fastening from -70° to 250°F, preventing loosening in dynamic applications
• Superior corrosion resistance from 18-8 stainless steel construction, ensuring long-term reliability in harsh industrial environments
• Precise component alignment with Class 2A thread fit and precisely machined 1/2" shoulder length, enabling accurate positioning in assemblies
• High strength-to-weight ratio delivering 70,000 psi tensile strength and Rockwell B55 hardness for demanding mechanical applications
• Dual drive compatibility featuring both socket and slotted drive styles for flexible installation with standard tools
• Regulatory compliance assurance meeting RoHS 3 and REACH standards for global manufacturing and environmental safety requirements
• Optimized for production efficiency with coarse UNC threading and right-hand direction for rapid assembly in high-volume operations

Professional Applications & Engineering Value

This 4-40 UNC shoulder screw delivers critical engineering solutions where precise component alignment and vibration resistance are paramount. The 18-8 stainless steel construction provides exceptional corrosion resistance for machinery exposed to moisture, chemicals, or outdoor elements, while the nylon patch thread locker eliminates the need for separate locking components in applications subject to constant vibration or thermal cycling. The precisely machined shoulder with tight diameter tolerance serves as an accurate locating surface for gears, bearings, and rotating components in industrial automation equipment, precision instruments, and electromechanical assemblies. The combination of 70,000 psi tensile strength and Rockwell B55 hardness ensures reliable performance in high-stress applications without compromising the corrosion-resistant properties of the material.

Specification Summary & Compliance

This precision shoulder screw features Class 2A thread fit per UNC standards with a 4-40 thread size and coarse thread spacing. The shoulder maintains precise dimensions with diameter tolerance of -0.001" to 0" and length tolerance of 0" to 0.002". Manufacturing complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental compliance for global industrial applications. The component meets standard industrial specifications for right-hand thread direction and incorporates permanent nylon patch thread locking technology rated for temperature extremes from -70° to 250°F.