S-94128A146 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability - Alloy steel construction with Rockwell C32 hardness provides superior resistance to wear and deformation in demanding industrial environments.
• Precise Component Alignment - A precisely machined 1/8" diameter shoulder with a tight tolerance ensures accurate positioning and reduces assembly misalignment.
• Superior Thread Reliability - Class 3A thread fit for the 4-40 UNC coarse thread offers a tighter, more secure fastening with reduced risk of loosening under vibration.
• Space-Saving & Secure Installation - The headless, slotted drive design allows for flush mounting in confined spaces while enabling easy installation and removal.
• Consistent Shoulder Dimensions - A controlled shoulder length of 3/4" with minimal tolerance ensures repeatable performance in automated or precision assemblies.
• Environmental & Regulatory Compliance - Meets RoHS 3 and REACH standards, ensuring safety and environmental responsibility for global supply chains.
• Optimized for High-Stress Applications - The right-hand coarse thread design facilitates quick assembly and provides strong holding power in dynamic load conditions.

Professional Applications & Engineering Value

This precision shoulder screw is engineered to address critical alignment and durability challenges in industrial machinery. The alloy steel material, hardened to Rockwell C32, ensures long-term performance in high-stress environments, resisting shear forces and fatigue. The Class 3A thread fit for the 4-40 UNC coarse thread guarantees a secure, vibration-resistant connection, essential for moving parts in automation equipment, robotics, and precision instruments. The headless slotted drive allows for a clean, low-profile installation, ideal for applications where space is limited and a smooth surface is required. By providing a reliable shoulder for bearing rotational loads or acting as a pivot, this screw minimizes component wear and maintenance downtime, delivering consistent engineering value in assembly lines and mechanical systems.

Specification Summary & Compliance

This shoulder screw adheres to precise dimensional standards, including a Class 3A thread fit for the 4-40 UNC coarse thread, ensuring tight tolerances and reliable performance. The shoulder features a diameter of 1/8" with a tolerance of -0.001" to 0", and a length of 3/4" with a tolerance of 0" to 0.005", supporting precise shoulder fit applications. It is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious industrial use without hazardous substances.