S-91259A143 3/4"-10 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 140,000 psi tensile strength and 84,000 psi minimum shear strength for reliable performance in high-stress applications.
• Superior corrosion resistance provided by the black oxide finish, extending service life in harsh industrial environments.
• Precision alignment and reduced wear due to the 1" shoulder diameter with tight tolerances (-0.004" to -0.002") for accurate component positioning.
• High-strength alloy steel construction with Rockwell C32 hardness ensures durability and resistance to deformation under heavy loads.
• Secure and efficient installation with a knurled socket head and 1/2" hex drive, preventing tool slippage and enabling high torque application.
• Reliable thread engagement through Class 3A UNC coarse threads, offering consistent fastening and vibration resistance.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety, quality, and environmental responsibility.

Professional Applications & Engineering Value

This heavy-duty shoulder screw is engineered to address critical challenges in industrial and mechanical applications where precision, strength, and durability are paramount. The alloy steel material, combined with a black oxide finish, provides excellent resistance to corrosion and wear, making it ideal for use in machinery, automation systems, and heavy equipment. The 1" shoulder diameter with tight tolerances ensures accurate alignment of components, reducing misalignment and wear in pivoting or rotating assemblies. The UNC coarse threads and Class 3A thread fit facilitate quick installation and reliable performance in high-vibration environments. With a 5 1/2" shoulder length, it supports extended spacing needs, while the knurled socket head and hex drive allow for secure, high-torque fastening without stripping. This screw is a trusted solution for engineers seeking ASME B18.3 compliant components that enhance operational efficiency and reduce maintenance costs.

Specification Summary & Compliance

This shoulder screw features precise dimensions, including a 3/4"-10 UNC thread size with Class 3A thread fit for accurate engagement, and a shoulder diameter tolerance of -0.004" to -0.002". It meets ASME B18.3 specifications under ASTM A574, ensuring consistent manufacturing quality. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, adhering to environmental and safety regulations for hazardous substances.