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Hardwood Record — Veneer & Panel Section 



January 10, 1918 



they do not take part in planning and carrying out the 

 work. They might do so, however, if they think it worth 

 while to request it and help do it. 



TTiis country has reached a stage in its history when 

 figures showing details of production will possess greater 

 value than ever before. It was once thought hardly nec- 



essary to keep an itemized cost sheet of an operation, 

 provided the business could keep going. That stage is 

 past. Cost sheets are essential now if a manufacturer 

 is to meet the keen competition with which he is faced. 

 Figures which show the details of output are a sort of 

 cost sheet useful to the whole industry. 



Strength of Veneers 



HE EXTRAORDINARY DEMAND for veneers 

 for war purposes in boxes, panels, drums, elec- 

 tric batteries and numerous other articles, has 

 brought out the fact that no adequate series of tests has 

 ever been made to determine the strength of various 

 woods in the form of veneers. The strength of all the 

 commercial woods is well known, but in solid pieces only 

 — not in sheets. Those who hitherto have carried out 

 experiments to determine how strong the different woods 

 are have had solid pieces to work with, and the thin sheets 

 have received very little attention. 



Veneers have been given such scant consideration in 

 working out tables of strength for woods because they 

 were not much used except in positions where strength 

 was not a matter of vital importance. The situation is 

 changing rapidly because the war has expanded the field 

 which veneers are called upon to fill, and it has become 

 .lecessary to know how one wood compares with another 

 in strength. 



Sheets of veneer may be tested in different ways. The 

 sheet may be bent with the fold parallel with the grain; 

 or it may be bent with the fold across the grain. In the 

 former case the sheet will split if the force is sufficient; 

 but in the latter case a break will be across the grain. The 

 sheet will not show the same resistance both ways. It 

 will split more easily than it will break. In panel making 

 it is customary to lay the sheets both ways so that the 

 panel will not split. 



Perhaps lists will speedily be made to determine the 

 strength of veneer, and one wood can be compared with 

 another, but that has not yet been done to any great 

 extent. It is possible, however, to compare the strength 

 of most American woods, not as veneer, but as solid 

 wood. Very complete figures are available along that 

 line. In the absence of better data, these figures may 

 be accepted, and one wood's strength can be compared 

 with another. The figures which follow are calculated 

 from data published in Bulletin 5 56 of the Forest Service, 

 issued last September, the latest and best available. 



In order to make the comparison practical, yellow 

 birch is taken as the basis of comparison, and its strength 

 is placed at 1 00, and weaker woods fall below and 

 stronger go above. The following twenty-six woods are 

 fairly representative of the forests of the United States: 

 Wood Strength 



Cotton gum 85 



Red oak 90 



Douglas fir 91 



Cherry 93 



Beech 94 



White oak 97 



Longleaf pine 101 



Sugar maple 1 06 



White ash 106 



Black walnut 110 



Cork elm 110 



Shellbark hickory 120 



Black locust 160 



Yellow birch 100 



Basswood 58 



Cottonwood 62 



White pine 62 



Yellow poplar 65 



Chestnut 65 



Red spruce 66 



Hemlock 70 



Sycamore 76 



White elm 80 



Red gum 80 



Cypress 80 



Black gum 81 



Probably three-fourths of the veneers manufactured 

 in the United States are cut from the woods represented 

 in the foregoing list. As already stated, the data on 

 strength may not hold true for veneers in all cases, yet 

 it is probable that the comparisons given above will hold 

 in most instances. At least, a manufacturer who wished 

 to produce panels requiring great strength would scarcely 

 choose white pine, basswood and cottonwood veneers 

 for the work, but would rather take maple, oak, long- 

 leaf pine or some other that shows strong in tests on the 

 solid w^ood. 



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