S-90324A118 1/4"-20 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments and extended service life.
• Exceptional thread precision and reliability with a Class 3A fit and left-hand UNC threading, ensuring secure fastening in specialized applications.
• High mechanical strength offering 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding loads and stress conditions.
• Enhanced grip and tool engagement from the knurled socket head and hex drive, preventing slippage during installation and removal.
• Accurate component alignment facilitated by the precision shoulder with controlled diameter and length tolerances.
• Compliance with stringent environmental regulations, being RoHS 3 and REACH compliant for safe and responsible use.
• Durable material hardness rated at Rockwell B55, providing excellent wear resistance and deformation prevention.

Professional Applications & Engineering Value

This 1/4"-20 UNC left-hand shoulder screw is engineered to address critical alignment and threading challenges in industrial machinery, automation systems, and precision assemblies. The 18-8 stainless steel material ensures long-term corrosion resistance, while the Class 3A thread fit and left-hand UNC coarse thread provide reliable, reverse-thread security in rotating equipment to prevent loosening. The precision shoulder with tight tolerances acts as a sturdy alignment pin, minimizing part misalignment and reducing wear. Combined with a knurled socket head for non-slip tool engagement, this fastener delivers consistent performance in high-stress applications, from manufacturing jigs to conveyor systems, ensuring operational safety and reduced maintenance.

Specification Summary & Compliance

This shoulder screw adheres to UNC thread standards with a Class 3A thread fit for precise engagement. Key dimensional tolerances include a shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". It is manufactured to meet RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring environmental safety and regulatory adherence for industrial use.