S-91259A478 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws
Shoulder Screws
Image may differ from product. See technical specification for details.
Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
Key Features & Benefits at a Glance
- Exceptional strength and durability with 140,000 psi tensile strength and Rockwell C32 hardness, ideal for high-stress industrial environments.
- Precise alignment and reduced wear due to the 1-5/8" shoulder with tight tolerances, ensuring stable component positioning.
- Superior corrosion resistance from the black oxide finish, extending service life in demanding conditions.
- Reliable, high-precision threading with Class 3A fit and UNC coarse thread for secure fastening and easy assembly.
- Secure, non-slip installation featuring a knurled socket head with hex drive for improved grip and torque application.
- Broad industry compliance meeting ASME B18.3 and ASTM A574 standards, ensuring consistent quality and performance.
- Environmental and safety adherence with RoHS 3 and REACH compliance, suitable for regulated markets.
Professional Applications & Engineering Value
This 1/4-20 UNC shoulder screw is engineered to address critical alignment and load-bearing challenges in precision machinery, automation systems, and heavy-duty equipment. The alloy steel construction and black oxide finish provide excellent resistance to wear and corrosion, reducing maintenance needs in harsh environments. The 1-5/8" shoulder length with minimal tolerances ensures accurate component spacing and rotation control, preventing misalignment and extending assembly life. Its Class 3A thread fit and coarse UNC threading offer reliable fastening with high vibration resistance, making it ideal for applications requiring repeated adjustments or high tensile strength. The socket head with knurling enhances installation efficiency, allowing for secure tool engagement in confined spaces.
Specification Summary & Compliance
This shoulder screw maintains Class 3A thread fit per UNC standards, with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005" for precise dimensional accuracy. It conforms to ASME B18.3 and ASTM A574 manufacturing specifications, ensuring consistent performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting safe and environmentally responsible usage.
