S-91259A412 8-32 ASME B18.3, ASTM A108 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength: Withstands up to 140,000 psi for reliable performance in high-stress applications.
• Precision Thread Fit: Class 3A thread fit ensures tight, secure fastening with minimal backlash.
• Enhanced Durability: Alloy steel construction with black oxide finish provides excellent corrosion resistance and wear protection.
• Superior Torque Transmission: Knurled socket head with hex drive allows for high torque application without slippage.
• Accurate Shoulder Dimensions: Tight tolerances on shoulder diameter and length ensure precise alignment in assemblies.
• Broad Industrial Compliance: Meets ASME B18.3, RoHS 3, and REACH standards for safe, reliable use in regulated environments.
• Coarse UNC Threads: Facilitates quick assembly and disassembly, reducing installation time and labor costs.

Professional Applications & Engineering Value

These 8-32 UNC shoulder screws are engineered to address critical alignment and load-bearing challenges in industrial machinery, automotive systems, and precision equipment. The alloy steel material, combined with a black oxide finish, offers superior resistance to corrosion and mechanical wear, extending service life in harsh environments. The Class 3A thread fit and precise shoulder dimensions ensure minimal play, reducing vibration-induced failures and maintaining component alignment. Ideal for applications requiring exact positioning, such as in robotics, conveyor systems, and assembly jigs, these screws deliver consistent performance under high tensile loads, supported by their 140,000 psi tensile strength and Rockwell C32 hardness. The knurled socket head with hex drive enhances grip during installation, preventing tool slippage and ensuring reliable torque transmission in confined spaces.

Specification Summary & Compliance

This product adheres to Class 3A thread fit for precise engagement and UNC coarse threads (8-32 size) with a thread diameter of 0.164". Shoulder dimensions include a diameter of 3/16" (tolerance: -0.004" to -0.002") and length of 1 3/4" (tolerance: -0.005" to 0.005"), ensuring accurate fit in assemblies. Manufactured in compliance with ASME B18.3 specifications and material standards per ASTM A108, it is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use.