Hardwood

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Beech is a typical temperate zone hardwood
Beech is a typical temperate zone hardwood
For the record label, see Hardwood Records.

The term hardwood designates wood from broad-leaved (mostly deciduous, but not necessarily, in the case of tropical trees) or angiosperm trees. Hardwood contrasts with softwood, which comes from conifer trees. On average, hardwood is of higher density and hardness than softwood, but there is considerable variation in actual wood hardness in both groups, with a large amount of overlap; some hardwoods (e.g. balsa) are softer than most softwoods, while yew is an example of a hard softwood. Hardwoods have broad leaves and enclosed nuts or seeds such as acorns. They often grow in subtropical regions like Africa and also in Europe and other regions such as Asia. The dominant feature separating hardwoods from softwoods is the presence of pores, or vessels. [1]

SEM images showing the presence of pores in hardwoods (Oak, top) and absence in softwoods (Pine, bottom)
SEM images showing the presence of pores in hardwoods (Oak, top) and absence in softwoods (Pine, bottom)

Hardwood species are more varied than softwood. There are about a hundred times as many hardwood species as softwoods. The vessels may show considerable variation in size, shape of perforation plates (simple, scalariform, reticulate, foraminate), and structure of cell wall (e.g. spiral thickenings).

Hardwoods are employed in a large range of applications including (but not limited to): construction, furniture, flooring, utensils, etc.

Hardwoods are generally more resistant to decay than softwoods when used for exterior work.[citation needed] However, solid hardwood joinery is expensive compared to softwood (in the past, tropical hardwoods were easily available but the supply is now restricted due to sustainability issues[citation needed]) and most "hardwood" doors, for instance, now consist of a thin bonded to medium-density fibreboard (MDF).

[edit] See also

Wood flooring

[edit] References

  1. ^ CRC Handbook of Materials Science, Vol IV, pg 15
  • Schweingruber, F.H. (1990) Anatomie europäischer Hölzer—Anatomy of European woods. Eidgenössische Forschungsanstalt für Wald, Schnee und Landscaft, Birmensdorf (Hrsg,). Haupt, Bern und Stuttgart.
  • Timonen, Tuuli (2002). Introduction to Microscopic Wood Identification. Finnish Museum of Natural History, University of Helsinki.
  • Wilson, K., and D.J.B. White (1986). The Anatomy of Wood: Its Diversity and variability. Stobart & Son Ltd, London. xx

[edit] External links