Question: This question relates to ISO tank container dimensions. “We are going to set a concrete foundation for our tank container which we will use for storage purposes. Is a 20′ ISO tank exactly 20′ long? And what is the exact width?”
Tank Guru: Please see attached chart of ISO tank container dimensions. You will note that a 20′ tank container is actually 19′-10.5″ long from end-to-end (6058 mm). The overall width is 8′ (2438 mm) and both of these dimensions refer to the distance from the outside faces of the corner castings.
A standard tank container is considered a “1CC” shipping container as defined by ISO 668 (https://en.wikipedia.org/wiki/ISO_668). Center-to-center of the holes in the bottom castings are 5853mm and 2259mm, respectively for length and width.
Good luck! We sell a lot of these portable tanks into storage service, because it’s hard to find the same value for a stainless steel, pressure-rated tank.