S-94128A145 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Thread Precision - Class 3A thread fit ensures superior engagement and vibration resistance in critical assemblies
• Optimized Shoulder Geometry - Precise 1/8" diameter shoulder with minimal tolerances provides accurate component positioning and alignment
• Enhanced Material Strength - Alloy steel construction with Rockwell C32 hardness delivers reliable performance under mechanical stress
• Simplified Installation - Slotted drive design allows for straightforward assembly with standard tools while maintaining headless profile
• Robust Thread Design - 4-40 UNC coarse threads offer excellent pull-out resistance and faster installation in various materials
• Regulatory Compliance Ready - Meets RoHS 3 and REACH environmental standards for global manufacturing applications
• Consistent Dimensional Stability - Tight shoulder length tolerance (0" to 0.005") ensures repeatable performance in precision mechanisms

Professional Applications & Engineering Value

This precision shoulder screw addresses critical alignment challenges in industrial applications where component positioning accuracy is paramount. The alloy steel construction with Rockwell C32 hardness provides the necessary strength to withstand rotational forces and mechanical loads in automated equipment, while the Class 3A thread fit maintains secure fastening in high-vibration environments. The precise shoulder diameter of 1/8" serves as a reliable locating feature in assemblies requiring exact component spacing, particularly in manufacturing jigs, robotic arms, and precision instrumentation. The headless slotted design offers flush mounting capabilities where clearance is limited, making it ideal for compact mechanisms and rotating assemblies where protruding fastener heads would cause interference.

Specification Summary & Compliance

This 4-40 UNC shoulder screw features Class 3A thread tolerances per unified screw thread standards, with precise shoulder dimensions maintaining -0.001" to 0" diameter tolerance and 0" to 0.005" length tolerance. Manufactured from alloy steel with Rockwell C32 hardness, the fastener complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for international industrial applications requiring strict material compliance.