S-91259A578 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws
Shoulder Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Exceptional strength and durability with 140,000 psi tensile and 84,000 psi shear strength, ideal for high-stress industrial applications.
- Superior corrosion resistance thanks to the black oxide finish, extending service life in harsh environments.
- Precise Class 3A thread fit ensures reliable, secure fastening with minimal risk of loosening under vibration.
- Knurled socket head provides enhanced grip for easy installation and removal with standard hex tools.
- Accurate shoulder dimensions with tight tolerances for consistent alignment and smooth rotational movement in assemblies.
- Compliance with ASME B18.3 and material standards guarantees consistent quality and interchangeability.
- RoHS 3 and REACH compliant for safe use in regulated industries and global markets.
Professional Applications & Engineering Value
This alloy steel shoulder screw with 1/4-20 UNC coarse threads and black oxide finish is engineered to address critical industrial challenges. The 7/16" shoulder length and precise diameter tolerances provide a stable pivot point or bearing surface, reducing wear in machinery and equipment. Its high tensile and shear strength makes it suitable for heavy-duty applications like automotive assemblies, robotics, and conveyor systems, where reliable fastening solutions are essential. The socket head with hex drive allows for easy access in confined spaces, while the Class 3A thread fit ensures vibration resistance, minimizing maintenance needs and downtime in demanding environments.
Specification Summary & Compliance
This shoulder screw features a 1/4"-20 UNC coarse thread with Class 3A fit for high precision. The shoulder has a diameter of 5/16" with tolerance from -0.004" to -0.002" and length of 1/2" with tolerance from -0.005" to 0.005". It meets ASME B18.3 specifications and is manufactured from alloy steel per ASTM A574, with a hardness of Rockwell C32. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations.
