Hardboard, also called high-density fiberboard (HDF), is a type of fiberboard, which is an engineered wood product.
It is similar to particle board and medium-density fiberboard, but is denser and much stronger and harder because it is made out of exploded wood fibers that have been highly compressed.Consequently, the density of hardboard is 31 pounds per cubic foot (500 kg/m3) or more and is usually about 50–65 pounds per cubic foot (800–1,040 kg/m3). It differs from particle board in that the bonding of the wood fibers requires no additional materials, although resin is often added. Unlike particle board, it will not split or crack.
Hardboard has long been used in furniture, but it is also popular for use in the construction industry and with trades as a temporary floor protector. Hardboard has become less popular over recent years due to new environmental targets in the construction industry to procure more sustainable temporary protection materials.
Hardboard is produced in either a wet or dry process. The wet process, known as the Mason Method, leaves only one smooth side while the dry processed hardboard is smooth on both sides. Masonite is produced using the wet process only.