S-95318A120 12.55 mm ID x 27.25 mm OD ASME B18.2.6M; ASTM F959 Tension-Indicating Structural Washers

Key Features & Benefits at a Glance

• Visual tension confirmation via orange dye that clearly indicates when the 49,000 N preload is achieved, reducing installation errors and ensuring joint integrity.
• Superior corrosion resistance from the galvanized steel coating, extending service life in harsh or outdoor industrial environments.
• High strength and durability with a Class 8.8 rating and Rockwell C37 hardness, providing reliable performance under heavy loads and vibration.
• Precision dimensional fit with a 12.55 mm ID and 27.25 mm OD designed for M12 bolts, ensuring easy installation and uniform load distribution.
• Compliance with major industry standards including ASME B18.2.6M and ASTM F959, guaranteeing interchangeability and performance consistency.
• Environmental regulation adherence with RoHS 3 and REACH compliance, making it suitable for global supply chains and regulated industries.
• Controlled thickness range (2.600mm-4.600mm) for consistent compression and accurate tension indication across production batches.

Professional Applications & Engineering Value

This M12 tension indicating washer is engineered for critical bolting applications where precise preload is non-negotiable. The galvanized steel construction resists corrosion in demanding environments like structural steelwork, heavy machinery, and infrastructure projects. The orange tension-indicating dye provides a fail-safe visual check, eliminating guesswork and preventing under or over-torquing—common causes of joint failure. By integrating ASME B18.2.6M and ASTM F959 specifications, it ensures dimensional accuracy and reliable performance in high-stress assemblies, reducing maintenance needs and enhancing operational safety. Its metric sizing and standardized design make it ideal for OEMs and MRO teams requiring repeatable, verifiable tension control.

Specification Summary & Compliance

This washer meets dimensional and performance standards per ASME B18.2.6M and ASTM F959, with precise metric dimensions: 12.55 mm ID, 27.25 mm OD, and a thickness range of 2.600 mm to 4.600 mm. The Class 8.8 material grade and Rockwell C37 hardness ensure mechanical reliability. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), adhering to environmental and safety regulations for industrial use worldwide.