SHORTLEAF PINE: IMPORTANCE AND MANAGEMENT. 9 
purpose. Other woods much used for structural timbers are Doug- 
las fir, western hemlock, tamarack, Norway pine, loblolly pine, and 
western larch. Comparative tests of these in both a green and an 
air-seasoned condition, and for both structural sizes and small, clear, 
straight-grained pieces,’ give shortleaf a relatively high place in all 
strength values, including bending, compression, and shearing. ‘The 
values found in the various tests are shown in Table 6: 
TABLE 6.—Average strength values of shortleaf pine, air seasoned, and green 
structural timbers with ordinary defects, and small, clear specimens cut from 
them. 
Com- 
: pression 
Bending. Compression. a berellel to perpen-| Shear. 
g : dicular 
: Hori- to grain. 
Condition and ae yee 
size. F . : 
inch.| per Fiber Medu- -  |!Crushing| Modu- p 
sq. in. |stress at Magu: lus of Prusbing strength] lus of ieee Shearing 
elastic arene elas- ae Macc at maxi-| elas- Pwolnatic strength 
limit Pp ticity limit per|, @U™ ticity lamitnen 
Den renin per :PeT Toad per; per a sq. in. 
squimy | a: |'sqsin. rod lasqueine: |sqrtin. jecsaos 
Air seasoned struc- Pounds.| Pounds.|Pounds.|1,0001bs.| Pounds. | Pounds. |1,0001bs.| Pounds. | Pounds. 
tural sizes....... 12.4 364 | 4,675 | 6,57: 1,726 4,070 6,030} 1,961 W9Gs|R Se ee See 
Small specimens. -|......]........ et80y | 1250200) si92 \o.2o 2 6,380 |........ 926 1,135 
1G) Oe ee S| Pa ae ace ee ae 60 54 OG) se ciieat. al a eric SO zene: 
Green structural 
Sizes. Pb clrey t 12.1 332 | 3,237 | 5,548| 1,473] 2,460] 3,435] 1,548 350 [ada 
Small specimens. .|......]........ ASSO feeds MLO py Ue 395, |eaeo sie BYU osodoce 400 704 
+) ARMA Sa aan elem eaters Sete 74 72 LOG) 352: 96. Fag tstess| Soom EOnG 
1 Tables 1, 2, and 10 to 15, Forest Service Bulletin 108, ‘‘ Tests of Structural Timbers.’’ 
Though true longleaf pine averages heavier, stronger, and tougher, 
many pieces of shortleaf have greater density, strength, and tough- 
ness than the average longleaf pine. Also some longleaf pine lacks 
density and is weaker than the average of the other species, the den- 
sity or dry weight of the wood being a much better criterion of the 
strength than the species. 
USES.? 
The general uses of shortleaf pine are as varied as those of long- 
leaf and the two go together without preference or prejudice for many 
purposes. For heavy building and structural work, however, where 
the architect desires timber to sustain pressure and withstand shocks, 
longleaf is usually preferred. Because of a high degree of strength 
and elasticity, the heavier classes of shortleaf* are being substituted 
for longleaf and are giving practically the same service. This recent 
1 Conducted by the Forest Products Laboratory, Madison, Wis. 
* Based in part upon State cooperative wood manufacturing studies and Forest Service 
Bulletin 99, “ Uses of the Commercial Woods of the United States: Pines,” pages 17 to 20. 
’ Timber having the same density as longleaf. rs 
6497°—Bull. 308—15 2 
