Kai USA is the manufacturer of Zero Tolerance knives. Kai USA manufactures everyday carry knives, kitchen cutlery and tactical and professional knives. Along with Zero Tolerance knives, it also manufactures Kershaw knives, Shun cutlery and Kai housewares.
Kai USA is a part of the Kai Group. Founded in 1908, the Kai Group has its headquarters in Tokyo, Japan. The Kai Group is best known for its companies that produce cutlery and related products such as razors, garment scissors, nail clippers, and industrial blades. The Kai Group also has several subsidiaries that manufacture kitchen utensils, confectionery utensils and professional beauty-care products.