By now, your old grate in your fireplace or stove is quite deformed. It can no longer be measured properly either. No problem: orientate yourself on the hollow in which the grate is located. Measure these and subtract at least 5 mm on each side. Why? Because metal expands with heat. i.e. the rust definitely expands. If there is no space along its length, it stretches upwards and becomes hump-backed. You must therefore continue to ensure in the future that the gap between the grate and the trough is free of foreign bodies so that the grate can “work”. Also remember the correct position of the oven rack in the firebox. The conical spaces must become larger towards the bottom.