Trio Manufacturing is a 75-year-old family business that began when its founder, Samuel Rinsler, made the courageous decision to leave steady employment with a major aerospace and defense company and embarked on his entrepreneurial journey. While evaluating his former employer’s processes, he conceived one of the world’s first mechanical countersink gages. Along with two co-workers he left the large firm and nurtured his concept to fruition. Eventually, the 3 partners went their separate ways and Trio became a bona-fide family owned business that has been under the management of three generations of the same dedicated family. The family has grown the initial product to become the gold standard for fastener related measurement by all of the world’s leading commercial and military aircraft companies. Trio continues to manufacture the complete line of Trulok measuring instruments which can be viewed at www.trulok.com

By 1960, Trio had firmly established itself as a world class builder of precision gages. This reputation led to Trio being invited to bid on machined flight parts and assemblies from companies such as McDonnell Douglas, Hughes and Menasco. One job led to another, and Trio quickly built a name as a first rate supplier of close tolerance parts. By 1965, Trio launched its contract manufacturing division to support the burgeoning Southern California aerospace industry.

After Mr. Rinsler’s passing in 1994, his grandchildren, Michael and Brian Hunkins embarked on a major exspansion that the founder would be proud of. This growth resulted in the acquisition of state-of-the-art machinery , additional manpower and a move to a larger facility in El Segundo California. By 1997, Trio had outgrown its building which required it to move to its present home, a 40,000 square foot state of the art facility.

Trio has continued to make considerable investments in the latest machine tool technology as evidenced by the 2017 opening of our high production wing. It features multiple palletized and multi access machining centers for lights out production of entire part families. Our commitment to upholding the high standard set by our founder has not wavered and we look forward to next chapter in our illustrious history.