S-91259A453 3/4"-10 ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Capacity: With 140,000 psi tensile strength and Rockwell C32 hardness, this shoulder screw reliably handles high-stress applications without deformation or failure.
• Precision Thread Engagement: Class 3A thread fit ensures tight, secure fastening with minimal backlash, ideal for assemblies requiring exact alignment and vibration resistance.
• Enhanced Corrosion Protection: Black oxide finish provides a durable barrier against rust and wear, extending service life in harsh industrial environments.
• Secure Grip & Easy Installation: Knurled head and 1/4" hex drive allow for firm tool engagement and straightforward torque application, reducing installation time and slippage risks.
• Accurate Shoulder Positioning: Tight shoulder diameter and length tolerances (-0.004" to +0.005") enable precise component location and smooth rotational movement in machinery.
• Robust Material Performance: Alloy steel construction offers superior strength-to-weight ratio and fatigue resistance, suitable for repetitive or heavy-duty cycles.
• Broad Compliance & Reliability: Meets ASTM A574 specifications and is RoHS 3 & REACH compliant, ensuring material safety and consistent quality for global supply chains.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical alignment and durability challenges in industrial machinery. The 3/4"-10 UNC coarse thread with Class 3A fit ensures rapid assembly and secure retention under dynamic loads, minimizing the risk of loosening in vibrating equipment like conveyors or presses. The black oxide finish enhances corrosion resistance, making it suitable for environments exposed to moisture or chemicals without compromising dimensional stability. The precision-machined shoulder, with controlled diameter and length tolerances, provides a reliable pivot or spacer in assemblies such as gearboxes, pivoting arms, and robotic linkages, reducing wear on adjacent components. By combining high tensile strength (140,000 psi) with a knurled socket head for easy access, this screw streamlines maintenance and upgrades in industrial applications, delivering long-term performance and reduced downtime.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit per UNC standards, ensuring precise engagement and interchangeability. Manufacturing follows ASTM A574 for material and dimensional consistency, with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005" for accurate positioning. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing the absence of restricted substances for safe use in various industries.