Captains of Crush Grippers

Captains of Crush Grippers (commonly nicknamed "CoC") are a brand of torsion-spring grippers (a torsion spring fitted with two handles) designed, manufactured and sold by IronMind Enterprises, Inc., based in Nevada City, California. They are the official grippers of the Arnold Sports Festival, the GNC Grip Gauntlet, United States Arm Wrestling and the World’s Strongest Man contest.

Hundreds of videos have been posted online and numerous blogs have been written documenting efforts to close the grippers. IronMind founder and president Randall J. Strossen wrote a book in 2003, Captains of Crush Grippers: What They Are and How to Close Them, to address some of the myths and questions surrounding CoC Grippers. This book was revised, and the second edition published, in 2009. The grippers have also been featured in publications such as Stanford magazine, The Sacramento Bee, and BusinessWeek’s BW SmallBiz magazine.

Through IronMind’s certification program for people who have officially closed any of the three toughest models, Captains of Crush Grippers have become an “internationally recognized measure of strength.”

Torsion-spring grippers date back at least as far as the beginning of the 20th century, and are used for both testing and building grip strength. Historically, torsion-spring grippers were not considered serious training tools because, among other things, they were not very difficult to close.

In 1964, Iron Man Magazine advertised a new line of grippers called the "Super Heavy Iron Man Grip Developer." These grippers had steel handles and thick springs and an “arguably somewhat primitive” design, but what distinguished them from torsion-spring grippers of the past was how difficult the Iron Man grippers were to close. The Iron Man ad billed the grippers as the "world’s strongest grip[pers] of this type."

Iron Man Magazine had stopped advertising its grippers in 1977 due to lack of sales, but the grippers had some followers, one of whom was IronMind founder Randall J. Strossen. In 1990, Strossen contacted Warren Tetting, who had made the Iron Man Grippers, and asked if he would be interested in making grippers for IronMind. The design of the original Iron Man Grippers varied in such features as the diameter of their handles, whether or not the handles were knurled, and whether the grippers had keepers on the springs.

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Wikipedia