ISO 9001 Certificate

We know that when you use our rings in a product you sell, we become an extension of your organization. Grover’s Glendale, WI manufacturing facility is one of a select group of companies worldwide that is certified for ISO 9001:2015.

We are unique in the industrial piston ring marketplace with ISO 9001 : 2015 quality certification. Grover customers benefit from a high-performance management system based on these high-quality systems as well as extensive use of lean manufacturing principles that deliver consistently high levels of customer satisfaction.


Quality is never an accident; it is always the result of high intention, sincere effort, intelligent direction and skillful execution; it represents the wise choice of many alternatives.

- ​William A. Foster