2 BULLETIN 1007, U. S. DEPARTMENT OF AGRICULTURE. 



produces basswood lumber, principally in West Virginia, which is 

 similar to that of Tilia americana. There are several other species 

 of basswood in the United States, all of which have wood similar to 

 the common basswood species, but contribute only small quantities 

 of the timber. As the wood of these different species is very much 

 alike, it is not kept separate in the market and is sold as basswood. 



PROPERTIES OF THE WOOD. 



GENERAL APPEARANCE. 



The heartwood of basswood is creamy brown with occasional 

 darker streaks. The sap wood is wide and not sharply defined from 

 the heartwood. The wood has a very uniform appearance; the sap- 

 wood and, particularly, rapid-growth timber has a light-colored, 

 clean look very desirable for special purposes. Basswood occasionally 

 shows a curly growth, especially near the butt of the tree, which 

 gives it an attractive appearance. This is unusual, however, and 

 the wood does not normally possess a curly grain nor any figure, such 

 as is found in oak and birch, for instance. It is therefore painted a 

 uniform color or stained to imitate some other wood, when used for 

 such purposes as inside house finish and the exterior woodwork of 

 furniture. 



PHYSICAL AND MECHANICAL PROPERTIES. 



Basswood timber is light in weight, soft in texture, straight-grained, 

 and has low strength values and poor shock-resisting ability in general 

 comparison with other woods. Compared on the basis of density or 

 weight, basswood has nearly average values for most of its properties 

 but has slightly greater stiffness and much greater shrinkage for its 

 density than the average. In the classification of woods by the 

 Forest Products Laboratory of the Forest Service into eight groups, 

 according to results of tests for each of six physical and mechanical 

 properties, basswood is described as follows: 



Property: Classification. 



Density or weight Light. 



Strength as a beam or post Weak. 



Hardness Soft. 



Shock-resisting ability Poor. 



Stiffness Moderately limber. 



Shrinkage Moderate. 



Table 1 shows actual and comparative properties of basswood 

 timber, as determined by the Forest Service from a very large number 

 of tests. White oak is the wood generally used as a basis for com- 

 parison of properties. The composite values given are a combination 

 of several kinds of tests. The hardness value of basswood is very 

 low compared with white oak on this basis. This is also true of the 

 different strength values, particularly shock-resisting ability. 



