S-90324A008 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Corrosion-resistant performance with 18-8 stainless steel construction, ideal for harsh industrial environments
• Precise left-hand threading with 4-40 UNC coarse thread and Class 3A fit for reliable, vibration-resistant fastening
• High strength durability offering 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding applications
• Secure installation enabled by knurled socket head and 5/64" hex drive, reducing slippage during assembly
• Accurate shoulder dimensions with 1/8" diameter and 3/16" length for stable alignment in precision machinery
• Compliance assurance meeting RoHS 3 and REACH standards for safe, regulated industrial use
• Consistent hardness at Rockwell B55, ensuring long-term wear resistance and thread integrity

Professional Applications & Engineering Value

This left-hand thread shoulder screw is engineered to address critical challenges in precision assembly, such as counter-rotational forces in machinery and equipment requiring reverse-thread security. The 18-8 stainless steel material provides excellent corrosion resistance, making it suitable for industries like aerospace, automotive, and electronics where environmental factors can compromise fastener integrity. With its UNC coarse threading and Class 3A fit, it ensures tight tolerances and reduced loosening under vibration, while the knurled socket head and 5/64" hex drive facilitate easy, tool-secure installation in confined spaces. Ideal for use in jigs, fixtures, and rotating components, this shoulder screw delivers reliable performance in high-stress applications, enhancing operational safety and reducing maintenance needs.

Specification Summary & Compliance

This shoulder screw adheres to UNC thread standards with a Class 3A thread fit for precise engagement, and features a shoulder diameter of 1/8" with tight tolerances (-0.004" to -0.002") and shoulder length of 3/16" (±0.005"). It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and suitability for global industrial markets. Manufactured to maintain consistent mechanical properties, including a tensile strength of 70,000 psi, it meets rigorous quality standards for dependable performance in engineering applications.