oak is a very hard wood
There are various types of oak that vary in hardness but oak is a hardwood.
Hard wood
There is no fruit that grows on an oak tree. Oak trees will produce acorns, a hard and heavily shelled nut.
Oak. Even oak will compress over time.
Maple, Hickory and Oak come to mind.
oak is the most common I know
Maple, Hickory and Oak come to mind.
Work hard.
Probably oak, that is the traditional hard wood for the old wooden sailing ships.
ply wood and hard wood floors
Normally hard such as red oak