S-92981A720 M20 ASME B18.3.3M Shoulder Screws

Key Features & Benefits at a Glance

• Superior Strength & Durability: Crafted from high-strength alloy steel with Rockwell C32 hardness and 140,000 psi tensile strength, ensuring reliable performance in high-stress applications and reducing the risk of fastener failure.
• Enhanced Corrosion Resistance: The black oxide finish provides a durable protective layer, significantly increasing the screw's lifespan in challenging industrial environments and reducing maintenance needs.
• Precise Alignment & Positioning: Features a 24mm shoulder diameter with a tight tolerance of -0.072 to -0.01 mm, offering excellent bearing surface and accurate component location for assemblies requiring strict alignment.
• Secure & Efficient Installation: The 12 mm hex socket head design allows for high-torque application with standard tools, ensuring a tight, secure fit and simplifying the assembly process.
• Optimized Thread Engagement: The M20x2.5 coarse right-hand thread with Class 4g6g fit ensures easy, reliable engagement and high resistance to vibrational loosening in demanding machinery.
• Robust Shear Strength: A minimum shear strength of 84,000 psi provides exceptional resistance to transverse loads, making it ideal for pivot points and heavy-duty rotational applications.
• Guaranteed Compliance & Quality: Manufactured to meet ASME B18.3.3M specifications and compliant with RoHS 3 and REACH regulations, ensuring material safety and international standard adherence.

Professional Applications & Engineering Value

This M20 shoulder screw is engineered to solve critical alignment and load-bearing challenges in industrial machinery. The alloy steel construction and black oxide finish combat wear and corrosion, extending service life in harsh conditions. Its precise 24mm shoulder diameter with controlled tolerances acts as a reliable pivot or axle, ensuring components like gears, pulleys, and linkages maintain perfect alignment under dynamic loads. The 80mm shoulder length provides a stable, unthreaded bearing surface, reducing wear on mating parts. The hex socket drive allows for high-torque installation in confined spaces, making it indispensable for precision assembly in automation, automotive, and heavy equipment manufacturing where reliable positioning is paramount.

Specification Summary & Compliance

This shoulder screw features a Metric M20x2.5 coarse thread with a Class 4g6g thread fit for standard industrial engagement. The shoulder diameter tolerance is tightly controlled at -0.072 to -0.01 mm, and the shoulder length tolerance is 0 to 0.25 mm, ensuring high dimensional accuracy. It is manufactured in compliance with the ASME B18.3.3M standard and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for global markets and restricted substance requirements.