S-8077A637 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance in harsh environments thanks to 316 Stainless Steel construction and protective Black Oxide finish.
• Exceptional mechanical strength with a tensile strength of 70,000 psi and a minimum shear strength of 35,000 psi for demanding applications.
• Precision alignment and smooth rotation ensured by the 2 1/2" shoulder with a controlled diameter tolerance and standard fit.
• High-reliability fastening with a Class 3A thread fit on the 1/4"-20 UNC coarse thread, minimizing the risk of loosening.
• Secure and easy installation provided by the knurled socket head with a 3/16" hex drive, offering excellent grip and torque transmission.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring quality and environmental safety.
• Durable and long-lasting performance backed by a Rockwell B79 hardness, ideal for repetitive use in industrial settings.

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 significantly enhances corrosion resistance, making it suitable for environments exposed to moisture, chemicals, and varying temperatures. The 1/4"-20 UNC coarse thread with a Class 3A fit ensures secure, vibration-resistant connections, while the precisely machined 2 1/2" shoulder provides stable alignment for rotating components like gears, pulleys, and linkages. The knurled socket head with a hex drive allows for high-torque installation without slippage, reducing assembly time and improving operational reliability in industrial applications.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, ensuring dimensional accuracy and performance reliability. The thread is manufactured to a Class 3A fit for tight tolerances, with a shoulder diameter tolerance of -0.004" to -0.002" and a shoulder length tolerance of -0.005" to 0.005". The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally conscious and regulated industries.