S-94128A166 1/4"-20 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability & Strength: Crafted from high-strength alloy steel with Rockwell C32 hardness for superior resistance to wear and deformation in demanding applications.
• Precise Shoulder Alignment: Features a 5/16" shoulder diameter with tight tolerance (-0.001" to 0") and 1" shoulder length for accurate component positioning and reduced assembly play.
• Reliable Thread Engagement: Class 3A thread fit ensures consistent, secure fastening with minimal backlash in high-vibration environments.
• Space-Saving Headless Design: Headless slotted drive allows for flush mounting in confined spaces while providing easy installation with standard tools.
• Coarse UNC Thread Efficiency: 1/4"-20 UNC coarse threads enable quick assembly and disassembly, reducing labor time in production lines.
• Environmental Compliance: Meets RoHS 3 and REACH regulations, ensuring safe use in electronics, machinery, and other regulated industries.
• Right-Hand Thread Convenience: Standard right-hand thread direction simplifies installation and aligns with common industrial practices.

Professional Applications & Engineering Value

This precision shoulder screw is engineered to address critical alignment and stability challenges in industrial assemblies. The alloy steel construction, combined with Rockwell C32 hardness, provides exceptional fatigue resistance, making it ideal for rotating machinery, pivoting mechanisms, and precision instruments where repeated motion can cause wear. The precise shoulder fit (5/16" diameter with minimal tolerance) acts as a reliable datum for components like gears, bearings, or linkages, eliminating misalignment and reducing stress concentrations. With its headless slotted drive and UNC coarse threads, it streamlines maintenance in tight spaces, while the Class 3A thread fit ensures vibration-resistant connections in automotive, aerospace, and automation systems. This design minimizes downtime and enhances operational reliability in high-stakes environments.

Specification Summary & Compliance

This shoulder screw adheres to UNC thread standards with a 1/4"-20 thread size and Class 3A thread fit for high-precision applications. The shoulder diameter (5/16") and length (1") maintain tight tolerances (e.g., shoulder diameter: -0.001" to 0"; shoulder length: 0" to 0.005") to ensure consistent performance. Manufactured from alloy steel with Rockwell C32 hardness, it complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and usage.