Tag Washer Frequently Asked Questions
Below are answers to some of the most common questions about tag washers.
What are tag washers?
Tag washers are flat washers with a protruding tab or ear that can be bent up against a fastener flat to lock the fastener in position and prevent loosening from vibration. The tab is bent against a wrench flat on a bolt or nut after tightening, creating a mechanical lock that prevents rotation without requiring thread-locking compounds or additional locking hardware. Tag washers are also used as identification tags, labeling components with part numbers or assembly codes.
How do tag washers prevent fastener loosening?
After the fastener is torqued to specification, the tab of the tag washer is bent 90 degrees up against one of the flats of the nut or bolt head using a punch or pliers. The bent tab mechanically blocks rotation of the fastener, preventing it from loosening under vibration or cyclic loading. This is a reliable, low-cost positive locking method used in aerospace, automotive, and industrial equipment applications.
What applications use tag washers?
Tag washers are used in aerospace and defense equipment, automotive engines and transmissions, industrial machinery, marine hardware, and any vibration-intensive application where fasteners must be positively locked against loosening. They are also used as component identification tags in complex assemblies where parts need to be labeled or serialized without separate tag hardware.
What materials are tag washers available in?
Tag washers are produced in steel, stainless steel, brass, aluminum, and copper. Material selection depends on the required tab bendability, corrosion resistance, and temperature requirements of the application. Contact us to specify the material needed.
Can you produce custom tag washers?
Yes. We manufacture custom tag washers to your OD, ID, tab dimensions, and thickness specifications in a range of materials. Contact us via the Quick Quote form or call NY (631) 273-8282 or SC (803) 366-3250.
Are your tag washers made in the USA?
Yes. All tag washers are manufactured in the United States under our ISO 9001:2015 certified Quality Management System at our Hauppauge, NY (CAGE Code: 1L160) and Rock Hill, SC (CAGE Code: 4WUG7) facilities.
Looking for a different locking or odd-shaped configuration? Browse the full flat washers catalog to see every shape and material we offer.
