S-91259A152 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 and 84,000 psi shear strength, this screw reliably handles high-stress applications without failure.
• Precision Shoulder for Accurate Alignment – The 7" shoulder with tight diameter and length tolerances ensures stable component positioning and reduces assembly misalignment.
• Superior Corrosion Resistance – Black oxide finish provides durable protection against rust, extending service life in harsh industrial environments.
• High-Strength Alloy Steel Construction – Made from Rockwell C32 hardened alloy steel for excellent durability and wear resistance under repetitive loads.
• Secure and Efficient Installation – Class 3A thread fit and coarse UNC threading enable quick, vibration-resistant fastening with reduced cross-threading risk.
• Easy Grip and Torque Application – Knurled socket head with 1/2" hex drive allows for firm tool engagement and high-torque tightening without slippage.
• Broad Regulatory Compliance – Meets ASME B18.3, ASTM A574, RoHS 3, and REACH standards, ensuring safety and suitability for global industrial use.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical alignment and load distribution challenges in precision machinery, automation systems, and heavy-duty equipment. The 7" shoulder length with minimal tolerance variation provides a stable bearing surface for rotating parts like gears, pulleys, and linkages, preventing axial movement and reducing wear. The black oxide finish enhances corrosion resistance in humid or abrasive settings, while the Class 3A UNC coarse threads ensure reliable engagement in high-vibration environments. Its 140,000 psi tensile strength and Rockwell C32 hardness make it ideal for applications requiring repeated disassembly and reassembly, such as in manufacturing jigs, conveyor systems, and mounting fixtures, where durability and precision are paramount.

Specification Summary & Compliance

This shoulder screw features a 3/4"-10 UNC Class 3A thread with coarse spacing for secure fastening, and a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005" to ensure precise fit. It is manufactured in compliance with ASME B18.3 and ASTM A574 specifications, and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, confirming its suitability for regulated industrial and international markets.