Definition as applicable to these rules

Bark Pockets : Patches of bark partially or wholly enclosed within the wood ; also known as " inbark "

Beehole : Holes in the wood caused by the larvae of Xyleutes ceramica .

Black Streak or Oil . Streak : These are lines blackish in colour . These are present in some pieces which are considered a defect from the point of view of appearance but do not effect the strength of the timber .

Blemish : Any feature which mars the appearance of a piece of timber ,but does not reduce its strength and durability ( e.g . Black Streak or Oil Streak or Chalk Veins ) .

Chalk Pockets : Cavities in wood which have become wholly or partially filled with white chalky substance.

Chalk Veins : Are lines whitish in color which are present in some pieces , which may in some cases mar its appearance but do not reduce the strength of the timber .

Cracks : Separation of the wood fibre in a longitudinal direction not penetrating as far as the opposite or adjoining side of the piece . They usually develop from strain during side of the piece . They usually develop from strain during seasoning . Surface ( or seasoning ) checks and end ( or heart ) check are to be distinguished .

Defect : Is a feature natural or induced that reduces the economic Value of a piece of timber by decreasing its strength or effecting adversely its working or finishing cualities or its appearance .

Discolouraiton : Is stain or variation from the natural color of the wood , cased by fungus attack or by oxidation through long exposure .

End Cracks : End Cracks are End Splits as a result of stress and strain in seasoning .

Grain : Reiers to the direction of the fibres of the wood , and is here termed a defect if the direction of the wood elements weakens the timber or presents difficulty in planing . ( See sloping grain)

Curly Grain : A wavy growth of the fibres which is difficult to plane and work .

Wavy Grain : A wavy growth of fibre usually appearing in flatswan timber giving the appearance which , in general trade , is known as the fiddle - back grain .

Rough Grain : Rough appearance on the surface of piece due to certain abnormalities of growth

Straight Grain : The principal wood cells running airly parallel to the length of a piece .

Cross Grain , Slope or Inclined Grain : The principal wood cells deviating more than 10 degrees to the longithdinal axis of the piece ( one in five )

Heart Centre : The small soft core ocdurring in the structural centre of a log around which the growth jof a tree is formed

Knot : A portion of a branch which has become embedded in the wood , and shows a clear pith in sawn timber . The crass section of a knot is usually circular or oval in shape and is measured by the mean diameter . Knots are classified as follows :

Sound Knot : Is solid across its face and except for its own pith is as hard as or harder than the surrounding wood to which it is joined ; it shows no indication of decay and is usually darker than the surrounding wood

Unsond Knot ; Is a knot which is softer than the surrounding wood because it contains decay . If the decay is advanced , there may be a hole in the center of the knot .

Spike Knot : A portion of the cpicormie branch , found embedded in the wood , and appearing in the form of a spike on one of the broad faces .

Sapwood : It is the outer band of living cells in a tree which are engaged in sap conduction and food storage . This is often of a different color and is not so durable as heartwood .

Shake : is used to describe a serious split or deep check . If it completely encircles the pith ,it is called a ring shake , if it does not completely encircle the pith , it is called a cup shake . If it extends from the pith outwards it is called a Heart or Star Shake .

Split : Split is a longicudinal separation of fibres which extend to the opposite face or the adjoining end of a piece .

Spring : Curvature such that if the piece of timber is laid on its ( tangential ) edge , it forms a flat arch .

Sun Cracks : Sun Cracks are cracks caused by surface checks . When it reaches an advanced stage , it causes a permanent separation of wood fibres attended by discolouration , along the line of the crack .

Wane ( Want ) : Is bark or the lack of wood on edge or corner of a piece of timber , usually caused by a portion of the original curved surface of a log remaining on the piece.