These were only made in 1942 due to the government trying to conserve the aluminum for the war effort. They were made of a low grade steel and porcelain covered but were not produced for long before the military went back to the other metals.
The U.S. Army acquired about five million M-1942 enameled steel canteens from six manufacturers. Most of the supply is believed to have gone to the Marine Corps and Navy, possibly because the Army did not want them.
Among the contractors who produced these are:
Vollrath Corp. (VOLLRATH)
U.S. Stoneware Co. (U.S.S.Co.)
Bellaire Enameling Co. (B.E.Co.)
Republic Stamping and Enameling Co. (REP or R.E.P.Co.)
Fletcher Enameling Co. (F.E. Co.)
Strong Manufacturing Co. (S.M. Co.)
Geuder, Paeschke & Fray (apparently unmarked)
As the manufacturer could not stamp their name into the botton of the canteens as they did the aluminum ones they instead were inked on the bottom of the canteen in white. There were both vertical and horizontal welded seams used in the design. Most are horizontal.
There were also enamel canteen cups which were made only in 1942 as well. (the total number is 26,634.) Manufactured by Landers, Frary & Clark (L.F.&C) Fletcher Enameling Company (FE Co.); Republic Stamping and Enameling (RSE Co.), and M.A.&Co. These are considered rare and are difficult to find. Most of the enameled canteens just used the standard aluminum cups as there were not near enough of the enameled cups made for all of them.
Both the canteens and cups were discontinued after the first year due to soldiers complaining about how they would chip causing sharp edges on the cups and contaminate thier drinking water. Most all porcelain canteens and cups are black, although there are a few that have a purplish tint.