Unmarked six inch outside calipers; unmarked six inch calipers; unmarked 5 1/2 inch calipers; unmarked 11 1/2 inch calipers; and 7 3/4 inch Calipers by J. STEVENS A & T CO. CHICOPEE FALLS MASS. USA. Stevens Arms & Tool Co. was an American firearms manufacturer founded by Joshua Stevens in 1864. The company introduced the .22 long rifle and mad a number of rifle, shotgun, and target pistol designs before being bought by Savage Arms in 1920. Stevens held several patents for calipers and dividers between 1885 and 1897, and made some of the finest ever known. Patent Papers