S-91259A134 3/4"-10 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability & Corrosion Resistance: Black oxide finish protects against rust and wear, extending service life in harsh industrial environments.
• Superior Tensile & Shear Strength: 140,000 psi tensile and 84,000 psi minimum shear strength ensure reliable performance under high-stress conditions.
• Precision Fit for Secure Assembly: Class 3A thread fit and controlled shoulder diameter tolerances guarantee accurate alignment and reduced vibration.
• Secure, Non-Slip Installation: Knurled socket head with 1/2" hex drive provides excellent grip and prevents tool slippage during tightening.
• Optimized for Heavy-Duty Applications: Alloy steel construction with Rockwell C32 hardness offers robust strength for demanding mechanical assemblies.
• Industry-Standard Compliance: Meets ASME B18.3 and ASTM A574 specifications, ensuring interchangeability and consistent quality.
• Environmental & Safety Assurance: RoHS 3 and REACH compliant, making it suitable for regulated industries and global supply chains.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical alignment and load-bearing challenges in precision machinery. The 3/4"-10 UNC coarse thread with Class 3A fit ensures fast, secure engagement, while the 2" shoulder length provides a stable pivot or bearing surface, minimizing misalignment in assemblies like rotating shafts, linkages, and jigs. The black oxide finish enhances corrosion resistance, vital for equipment exposed to moisture or chemicals. With a knurled socket head and 1/2" hex drive, installation is secure and efficient, reducing the risk of stripping. Ideal for automotive, aerospace, and heavy machinery, this screw delivers reliable performance where high tensile strength and dimensional accuracy are non-negotiable.

Specification Summary & Compliance

This shoulder screw adheres to tight dimensional tolerances, including a Class 3A thread fit for superior engagement and a shoulder diameter tolerance of -0.004" to -0.002" for precise alignment. It conforms to ASME B18.3 and ASTM A574 manufacturing standards, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting safe and sustainable industrial use.