S-8077A631 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel and Black Oxide finish, ideal for harsh environments and extended service life.
• High mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable performance under heavy loads.
• Precise thread engagement with Class 3A fit and UNC coarse threading, ensuring secure fastening and vibration resistance.
• Accurate shoulder dimensions with tight tolerances for consistent alignment and smooth rotation in assemblies.
• Easy installation and removal featuring a knurled socket head with hex drive for non-slip tool grip and efficient maintenance.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, guaranteeing quality and environmental safety.
• Versatile application fit due to coarse thread design and durable construction, suitable for various industrial machinery and equipment.

Professional Applications & Engineering Value

This 316 Stainless Steel Shoulder Screw is engineered to address critical challenges in industrial settings, such as misalignment and corrosion-induced failure. The Black Oxide finish enhances durability by providing an extra layer of protection against moisture and chemicals, while the UNC coarse threads facilitate quick assembly and disassembly, reducing downtime. With a Class 3A thread fit and precise shoulder dimensions, it ensures minimal play and optimal load distribution in applications like rotating shafts, pivots, and precision instruments. Its high tensile and shear strength makes it a reliable choice for demanding environments, from automotive to manufacturing, where consistent performance and long-term reliability are paramount.

Specification Summary & Compliance

The screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for superior accuracy and a shoulder diameter tolerance of -0.004" to -0.002". It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free from hazardous substances. Thread dimensions include a 1/4"-20 UNC coarse thread with a length of 3/4", and the shoulder features a length of 2" with a tolerance of -0.005" to 0.005", providing reliable performance in standardized industrial applications.