S-8077A639 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction and black oxide finish, ideal for harsh environments.
• High mechanical strength with 70,000 PSI tensile and 35,000 PSI shear strength for demanding industrial applications.
• Precise alignment and smooth rotation ensured by the Class 3A thread fit and standard shoulder fit.
• Easy installation and removal with hex socket drive and knurled head for enhanced grip.
• Reliable dimensional accuracy with tight shoulder diameter and length tolerances for consistent performance.
• Broad compliance with ASME B18.3 standards and environmental regulations like RoHS and REACH.
• Durable construction with Rockwell B79 hardness for long-lasting use in high-stress conditions.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision machinery, automation systems, and heavy-duty equipment. The black oxide finish enhances corrosion resistance, making it suitable for moist or chemically aggressive environments. Its 1/4"-20 UNC coarse thread and Class 3A fit provide secure fastening with minimal risk of loosening under vibration. The knurled head and hex drive facilitate easy handling and torque application, reducing assembly time. With a robust shoulder diameter of 3/8" and length of 1 3/4", it ensures precise component alignment and smooth rotational movement, ideal for pivots, bearings, and linkages in industrial applications.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, featuring a Class 3A thread fit for high precision. Key dimensions include a shoulder diameter of 3/8" with tolerance from -0.004" to -0.002", and shoulder length of 1 3/4" with tolerance from -0.005" to 0.005". It is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring environmental safety and regulatory adherence for global industrial use.