1917 



Hardwoods and Softwoods 



Ha Maxwell 



Editor's Note 



It is (luite "eiierallv kuuwu that Ihi' terms liardwoorl anil Kuttwoo.l do not refor spi'ciHi-all.v to 

 the liardness 01- the Vot'tne'i-: ot the woods, out serve rather to designate classes. No plan has 

 vet been aereed upon hv users generally for classifying woods in accoroance with physical hardness, 

 and relatively a sniall number ot species have won their ^vay to extensive use because ot their excep- 

 tional hardness or softness. Mowever, special demand due to these properties affords an interesting sutject 

 for study of the utilization of woods. 



ARTICLE FOUR 



In daily jiractice, some woods are classed as hardwoods, others as 

 softwoods. The line of separation between the classes is botanical, and 

 the distinction is not necessarily based on actual hardness or softness. 

 Woods of hard texture are not all in one division, nor are those that 

 are soft all in the other. The leaf which a tree bears determines 

 whether the wood shall be called hardwood or softwood, but the leaf 

 is no guide to the wood 's actual hardness or softness. It is simply the 

 test accepted by common consent. If the leaf is needle shaped, the 

 tree is a softwood, whether pine, fir, hemlock, spruce, yew, cypress, 

 larch, sequoia, tumion, torreya, or cedar. If the tree bears a broad 

 leaf, it is a hardwood, whether oak, cottonwood, beech, willow, ash, 

 basswood, gum, buckeye, maple, persimmon, or any other of the 450 

 broadleaf species of the United States. The distinction is clear-cut, 

 and if it is known what kind of leaf' any tree bears, its classification 

 as hardwood or softwood can be determined then and there. Palms 

 and cacti are outside of both classes. 



A classification based on actual hardness would be very different 

 from the system now in use, and it would be unsatisfactory and would 

 lead to interminable disputes. Attempts at such classification have 

 been made. In restricted regions some use is made of other classifica- 

 tions. In the Lake States some persons speak of "the hardwoods" 

 when they mean beech, birch, and maple, and nothing else. In some 

 parts of the southern cypress region they speak of ' ' hardwoods, soft- 

 woods, and' cypress, ' ' thus putting cypress in a class to itself. In soft- 

 ness, eyjiress fits in between white pine and buckeye, and there is no 

 jihysical or botanical reason why it should stand apart, though such a 

 thing might be desired for commercial reasons. 

 Quantities Compaked 



There is six times as much softwood as hardwood stumpage in the 

 United States; but if the species or kinds of trees are considered, there 



MACHINE FOR TESTING WOOD'S HARDNE.SS 



This is part of the equipment of the Forest Products Laboratory at Madison, 



Wis. A steel ball or point is forced into wood by slow and 



continuous pressure which is duly recorded. 



—18— 



are four hardwoods to one softwood. The hardwoods do not average 

 one billion feet in the entire country for each species, but the soft- 

 woods average twenty-five billion feet stumpage per species. A single 

 softwood, Douglas fir, could produce more lumber, if a clean cut were 

 made, than could be cut from all the hardwoods of the United States. 



Although in bulk the hardwoods amount to only one-sixth of the 

 softwoods, they are much richer in variety, finer and more diversified 

 in grain, more beautiful in appearance, and of wider range in color. 

 The strongest, stifCest, hardest woods of this country belong in the 

 hardwood class, but there are strong, hard, stiff woods in the other 

 class also. 



Both classes grow in all large divisions of the United States ; but the 

 bulk of the softwoods is west of the one-hundredth meridian and 

 most of the hardwoods east of that line. Hanlwoods west of the 

 Rocky Mountains are of relatively little value; but the quality 

 of the eastern softwoods, including the southern yellow pine, is not 

 inferior to the product of the western forests. 



The Hardness of Wood 



The ordinary user of wood tests its hardness by chopiiing it with an 

 ax, cutting it with a saw, boring with an auger, trying it with other 

 edged tools, or in some other experimental way. The test meets the re- 

 quirements of the majority of users, liut an exact record is not prac- 

 ■ ticable under such circumstances. A carpenter might belieye that 

 yellow poplar is softer than basswood, and his own experience might 

 warrant that conclusion : and on the same evidence he might assert 

 that oak is harder than ash. But if there were no records other than 

 his own opinion, he might find it difficult to convince another carpenter 

 who held a contrary opinion based on different experience. 



Exact measurements and dependable records are essential, and these 

 cannot be obtained by the rule of tliumb. Machines are in use by 

 laboratories for testing the hardness of woods in such a way that one 

 specimen may be compared with another. The machines work on the 

 ]irinciple of applying pressure — not blow's — to drive a point or an edge 

 into tlie wood a specified depth. The point to be forced into the wood 



PROCES.S OF IIAKI.XG SIUTTLKS 

 The shuttles in textile mills must give peculiar and exacting service and 



only American woods are considered wholly satisfactory 



dogwood and persimmon. 



