So Hop Hornbeam is the species I refer to as ironwood. (Ironwood means different things in different places in the world.) In NY near Canada where I cut it, ironwood grows up to maybe 16" in diameter. But in general it's a small tree--I think 50' tall would be a monster. In the NY woods I know it is very much known as a weed tree, in other words it displaces the valuable species like sugar maple, the oaks, etc. But, in that country (like E. Ontario) it's a valuable fuel wood. Cut all you have for firewood, and to give room for other species.