S-91259A310 7/8"-9 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Durability: Crafted from high-grade alloy steel with Rockwell C32 hardness, ensuring long-lasting performance in demanding industrial environments.
• Superior Corrosion Resistance: Black oxide finish provides enhanced protection against rust and wear, extending the screw's service life.
• High Load Capacity: With a tensile strength of 140,000 psi and shear strength of 84,000 psi, it reliably handles heavy-duty applications without failure.
• Precision Thread Fit: Class 3A thread fit guarantees tight, secure connections, reducing the risk of loosening under vibration or load.
• Easy Installation and Removal: Features a 5/8" hex drive and knurled head for improved grip, allowing for quick assembly and disassembly with standard tools.
• Versatile Shoulder Design: The 1 1/4" shoulder diameter and 2 1/2" length provide stable alignment and spacing in machinery and fixtures.
• Broad Compliance: Meets ASME B18.3 standards and is RoHS/REACH compliant, ensuring safety and environmental responsibility in global markets.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address common industrial challenges, such as misalignment and component wear. Its 7/8"-9 UNC coarse thread and Class 3A precision fit ensure reliable fastening in high-stress environments, from heavy machinery to automotive assemblies. The black oxide finish enhances corrosion resistance, making it ideal for applications exposed to moisture or harsh conditions. The knurled head and hex drive facilitate easy handling, reducing installation time and improving efficiency. By incorporating a robust shoulder design, it provides precise positioning and load distribution, minimizing downtime and maintenance costs in industrial applications like jigs, fixtures, and rotating equipment.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with UNC coarse threading for secure fastening. Dimensions include a shoulder diameter of 1 1/4" (tolerance: -0.004" to -0.002") and length of 2 1/2" (tolerance: -0.005" to 0.005"), ensuring high precision. It complies with ASME B18.3 manufacturing standards and is RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, supporting safe and sustainable use in various industries.