S-90069A110 0.167" ID x 0.322" OD ASME B18.21.1 Countersunk External-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior Vibration Resistance: External teeth bite into mating surfaces, preventing loosening under dynamic loads for enhanced assembly integrity.
• Corrosion-Resistant Durability: Zinc-plated steel construction provides reliable protection against rust, extending service life in demanding environments.
• Optimized Countersunk Fit: 82° countersink angle ensures flush seating in tapered screw heads, maintaining a smooth surface profile.
• Precision Sizing for No. 8 Screws: 0.167" ID and 0.322" OD deliver exact compatibility, eliminating play and ensuring uniform load distribution.
• High-Strength Material Performance: Rockwell C44 hardness offers excellent wear resistance and maintains tooth integrity under high torque.
• Industry-Standard Compliance: Manufactured to ASME B18.21.1 specifications, guaranteeing consistent quality and interchangeability.
• Environmental & Regulatory Safety: RoHS 3 and REACH compliant, ensuring safe use in global industrial supply chains.

Professional Applications & Engineering Value

This zinc-plated steel external tooth lock washer is engineered to solve critical vibration-induced failure in machinery, automotive, and structural assemblies. The external tooth design provides maximum grip on surfaces, effectively resisting rotational loosening from shock and dynamic stresses. With an 82° countersunk angle, it seamlessly integrates with tapered screw heads, preventing protrusion and maintaining aerodynamic or aesthetic surfaces. The Rockwell C44 hardness ensures teeth remain sharp and functional through repeated torque cycles, while the zinc plating defends against corrosion in humid or outdoor settings. Ideal for heavy-duty industrial applications, this washer enhances the reliability of No. 8 screw fastenings in equipment subject to constant motion or thermal cycling.

Specification Summary & Compliance

This washer meets dimensional and performance standards per ASME B18.21.1, with precise specifications including a 0.167" inner diameter, 0.322" outer diameter, and thickness of 0.017–0.021". The external tooth location and 82° countersink angle adhere to standard tolerances for consistent fit and function. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) confirms the absence of restricted substances, supporting use in regulated industries worldwide.