S-91259A583 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with alloy steel construction, providing 140,000 psi tensile strength and 84,000 psi shear strength for reliable performance in demanding applications.
• Superior corrosion resistance thanks to the black oxide finish, extending service life in harsh industrial environments.
• Precise alignment and smooth rotation enabled by the knurled socket head and Class 3A thread fit, ensuring secure fastening and reduced assembly time.
• High load-bearing capability from the 1" shoulder length with tight tolerances, offering stable support for moving parts in machinery.
• Easy installation and removal with the hex drive style and standard UNC coarse threads, facilitating quick maintenance and adjustments.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety, quality, and environmental responsibility.
• Enhanced wear resistance due to Rockwell C32 hardness, maintaining integrity under repetitive stress and vibration.

Professional Applications & Engineering Value

This shoulder screw is engineered to address common industrial challenges, such as misalignment and component wear in rotating assemblies. Made from alloy steel with a black oxide finish, it resists rust and corrosion, making it ideal for automotive, aerospace, and heavy machinery applications. The 1/4"-20 UNC coarse thread and Class 3A thread fit ensure tight, reliable connections, while the knurled socket head allows for easy torque application with standard hex tools. Its 1" shoulder length provides a precise pivot point or spacer, reducing friction and extending the life of connected parts in high-stress environments like conveyor systems or robotic arms.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC thread with Class 3A fit for high precision, along with a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005". It meets ASME B18.3 specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, ensuring it is free from hazardous substances and suitable for global industrial use.