[1] In April 1940, the Brazilian Army officer Plinio Cardoso was in Denmark visiting the Dansk Industri Syndicat factory on an official mission, when the Germans invaded the country.

[2] Some models and first prototypes of the submachine gun would have been developed and adapted inside the IMBEL factory in Itajubá, in partnership with the engineer Euclydes Bueno Filho, who would join Plinio to found INA.

[1][3][4] The first model of the INA submachine gun (M950) was heavily criticized by the military at the time due to its quality.

It was the first Brazilian firearms manufacturer to export products to the U.S. arms market, achieving great success with its Tiger revolver (exported to the U.S. market under the name Tiger), whose design was based on the Smith & Wesson Model 10 and used .32 S&W Long caliber.

[1][3] After years of accumulating debt, a reduction in the volume of exports of its products, the replacement of its old machine guns in the armed forces by the new Beretta M12s, and an alleged influence of the military government to close the manufacturer, INA closed its operations in 1972, selling its machinery and factory to Companhia Brasileira de Cartuchos.