S-97768A365 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Corrosion Resistance – 18-8 stainless steel construction combined with a black oxide finish ensures long-term reliability in harsh environments, reducing maintenance and replacement costs.
• Superior Thread Precision – Class 3A thread fit provides tighter tolerances for secure, vibration-resistant fastening in high-stress assemblies.
• High Tensile and Shear Strength – With 70,000 psi tensile and 35,000 psi minimum shear strength, this screw withstands heavy loads and mechanical stress without failure.
• Enhanced Grip and Alignment – Knurled head and standard shoulder design improve handling during installation and ensure precise component positioning.
• Wide Industry Compliance – Meets ASME B18.3 standards and is RoHS 3 and REACH compliant, ensuring safety and regulatory acceptance in global markets.
• Optimized Drive Efficiency – Hex socket drive (3/16") allows for easy installation with standard tools, reducing assembly time and risk of stripping.
• Durable Hardness – Rockwell B55 hardness offers excellent wear resistance, extending service life in repetitive or high-friction applications.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical alignment and load-bearing challenges in industrial settings. The 18-8 stainless steel material and black oxide finish provide robust corrosion resistance, making it ideal for machinery, automotive, and electronics applications exposed to moisture or chemicals. The 1/4"-20 UNC coarse thread with Class 3A fit ensures secure fastening, minimizing loosening under vibration. The knurled head enhances grip during manual or automated installation, while the precise shoulder diameter and length facilitate accurate spacing and rotational control in assemblies like pivots, bearings, and guides. By combining high tensile strength and compliance with ASME B18.3 standards, this screw reduces downtime and improves operational reliability in demanding environments.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC thread with Class 3A fit for high precision, and dimensions include a 3/8" shoulder diameter and 1" shoulder length with tight tolerances (e.g., shoulder diameter tolerance: -0.004" to -0.002"). It is manufactured in accordance with ASME B18.3 specifications and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material reliability.