Knots 
X
 
Spike Knot 
X
Intergrown Knot 
X
Black Tight Knot 
X
Black Loose Knot 
X
Encased Knot 
X
Unsound Knot 
X
Checked Knot 
X
Knot Hole 
X
Slough Knot Hole 
X
Lumber Characteristics - Knots:
 
Spike Knot
Found on vertical grain surfaces when the limb is cut either lengthwise or diagonally to the length of its axis.
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Intergrown Knot
Knot with its growth rings partially or completely intergrown with the growth rings of the surrounding wood.
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Black Tight Knot
Formed from a dead branch in the tree where the new tree growth surrounded it. The knot is tight because it is fixed by growth, shape or position, and will retain its place in the piece.
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Black Loose Knot
Formed from a dead branch in the tree where the new tree growth surrounded it. The knot is loose because it is not fixed by growth, shape or position, and can't be expected to retain its place in the piece.
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Encased Knot
A knot surrounded by bark or pitch. It is not intergrown with the surrounding wood.
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Unsound Knot
A knot that contains decay.
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Checked Knot
Seasoning checks in a knot, usually occuring from the pith to the edge.
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Knot Hole
A hole resulting from the loss of a knot.
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Slough Knot Hole
A slough knot hole running from the wide face to the edge.
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