S-90324A005 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments
• Superior thread engagement and vibration resistance through Class 3A precision thread fit for reliable assemblies
• High-strength performance with 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding applications
• Secure anti-loosening capability with left-hand thread direction in critical rotating machinery
• Easy installation and removal with knurled socket head and 5/64" hex drive for improved tool grip
• Precise component alignment through standard shoulder fit with controlled diameter and length tolerances
• Environmental compliance assurance meeting RoHS 3 and REACH standards for global manufacturing requirements

Professional Applications & Engineering Value

This 4-40 UNC left hand thread shoulder screw delivers critical engineering solutions where reverse rotation prevention and precise component positioning are paramount. The 18-8 stainless steel construction provides excellent corrosion resistance in manufacturing, automation, and marine environments, while the Class 3A thread fit ensures vibration-resistant assemblies in high-stress applications. The knurled socket head with hex drive allows for secure tool engagement in confined spaces, preventing slippage during installation. The standardized shoulder diameter and length with tight tolerances enable accurate alignment of moving parts in machinery, jigs, and fixtures. Particularly valuable in left-hand thread applications where conventional fasteners would loosen under counter-clockwise rotation, this shoulder screw maintains integrity in power transmission systems, rotating assemblies, and precision equipment where reliability cannot be compromised.

Specification Summary & Compliance

This precision shoulder screw maintains Class 3A thread fit per UNC standards with coarse thread spacing, ensuring superior engagement in industrial applications. Critical dimensions include 0.25" head diameter, 5/32" thread length, and shoulder diameter of 1/8" with tolerances of -0.004" to -0.002". The shoulder length of 1/8" features a tolerance range of -0.005" to 0.005" for precise component alignment. Manufactured from 18-8 stainless steel with Rockwell B55 hardness, the fastener delivers consistent performance across temperature variations. The product fully complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, making it suitable for global industrial applications requiring regulatory adherence.