S-94383A220 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability & Strength: Crafted from alloy steel with a 140,000 psi tensile strength and 84,000 psi shear strength to withstand high-stress applications and prevent mechanical failure.
• Superior Corrosion Resistance: Black oxide finish provides a protective layer, reducing oxidation and extending service life in demanding industrial environments.
• Precision Fit & Reliable Alignment: Class 3A thread fit ensures tight tolerances and secure fastening, minimizing backlash and improving assembly accuracy.
• Secure & Efficient Installation: Knurled socket head with a 5/32" hex drive offers excellent grip and torque transmission, reducing the risk of tool slippage during installation.
• Optimized for High-Load Applications: 7/16" shoulder diameter and 3/8" shoulder length provide stable bearing surfaces for pivoting parts, reducing wear and maintaining alignment.
• Industry-Standard Compliance: Meets ASME B18.3 and ASTM A574 specifications, ensuring consistent quality and performance in regulated sectors.
• Environmental & Safety Assurance: Compliant with RoHS 3 and REACH standards, making it safe for use in various industries without hazardous substances.

Professional Applications & Engineering Value

This 1/4"-20 UNC thread shoulder screw is engineered to address critical challenges in industrial applications where precision, strength, and reliability are paramount. The alloy steel construction, combined with a Rockwell C32 hardness, ensures exceptional resistance to wear and deformation under heavy loads, making it ideal for machinery, automotive assemblies, and precision instruments. The coarse UNC thread and Class 3A fit facilitate quick, secure fastening while maintaining alignment in dynamic systems. The black oxide finish enhances corrosion resistance, prolonging lifespan in harsh environments. Its knurled socket head design allows for efficient torque application, reducing installation time and improving operational safety in high-vibration settings.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC coarse thread with a Class 3A precision fit for exacting dimensional accuracy. The shoulder diameter is 5/16" with a tolerance of -0.004" to -0.002", and the shoulder length is 3/8" with a tolerance of -0.005" to 0.005", ensuring consistent performance. It complies with ASME B18.3 and ASTM A574 manufacturing standards, and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for safe and sustainable use.