“Oak wood has a density of about 0.75 g/cm3 (0.43 oz/cu in) creating great strength and hardness. The wood is very resistant to insect and fungal attack because of its high tannin content. It also has very appealing grain markings, particularly when quartersawn. Oak planking was common on high status Viking longships in the 9th and 10th centuries. The wood was hewn from green logs, by axe and wedge, to produce radial planks, similar to quarter-sawn timber. Wide, quarter-sawn boards of oak have been prized since the Middle Ages for use in interior panelling of prestigious buildings such as the debating chamber of the House of Commons in London and in the construction of fine furniture. Oak wood, from Quercus robur and Quercus petraea, was used in Europe for the construction of ships, especially naval men of war, until the 19th century, and was the principal timber used in the construction of European timber-framed buildings. Today oak wood is still commonly used for furniture making and flooring, timber frame buildings, and for veneer production. Barrels in which wines, sherry, and spirits such as brandy, Irish whiskey, Scotch whisky and Bourbon whiskey are aged are made from European and American oak. The use of oak in wine can add many different dimensions to wine based on the type and style of the oak. Oak barrels, which may be charred before use, contribute to the colour, taste, and aroma of the contents, imparting a desirable oaky vanillin flavour to these drinks. The great dilemma for wine producers is to choose between French and American oakwoods. French oaks (Quercus robur, Q. petraea) give the wine greater refinement and are chosen for the best wines since they increase the price compared to those aged in American oak wood. American oak contributes greater texture and resistance to ageing, but produces more powerful wine bouquets. Oak wood chips are used for smoking fish, meat, cheeses, and other foods.
Japanese oak is used in the making of professional drums from the manufacturer Yamaha Drums. The higher density of oak gives the drum a brighter and louder tone compared to traditional drum materials such as maple and birch. In hill states of India, besides fuelwood and timber, the local people use oak wood for making agricultural implements. The leaves are used as fodder during lean period and bedding for livestock.
The bark of the cork oak is used to produce wine stoppers (corks). This species grows in the Mediterranean Sea region, with Portugal, Spain, Algeria, and Morocco producing most of the world's supply.
Of the North American oaks, the northern red oak is the one of most prized of the red oak group for lumber, much of which is marketed as red oak regardless of the species of origin. It is not good for outdoor use due to its open capillaries unless the wood is treated. If the wood is properly treated with preservatives, it will not rot as quickly as cured white oak heartwood. The closed cell structure of white oaks prevent them from absorbing preservatives. With northern red oak, one can blow air through an end grain piece 10 inches long to make bubbles come out in a glass of water. These openings give fungus easy access when the finish deteriorates. Shumard oak, a member of the red oak subgenus, provides timber which is described as "mechanically superior" to Northern Red oak. Cherrybark oak is another type of red oak which provides excellent timber.
The standard for the lumber of the white oak group – all of which is marketed as white oak – is the white oak. White oak is often used to make wine barrels. The wood of the deciduous pedunculate oak and sessile oak accounts for most of the European oak production, but evergreen species, such as Holm oak and cork oak also produce valuable timber.
The bark of the White Oak is dried and used in medical preparations. Oak bark is also rich in tannin, and is used by tanners for tanning leather. Acorns are used for making flour or roasted for acorn coffee.
Oak galls were used for centuries as a main ingredient in iron gall ink, a kind of manuscript ink, harvested at a specific time of year. In Korea, oak bark is used to make shingles for traditional roof construction.
Oak has been listed as one of the 38 substances used to prepare Bach flower remedies, a kind of alternative medicine promoted for its effect on health. However, according to Cancer Research UK, "there is no scientific evidence to prove that flower remedies can control, cure or prevent any type of disease, including cancer".”