While no maximum specific gravity limitations are necessai--, it 
is worthy of note that greater uniformity of weight and strength can be 
obtained by removing the exceptionally dense stock. 
Table 2.— Minimum acceptable specific gravity values for aircraft ■■/pods 
: Specific gravity (based 
: on volume and weight 
: when oven- dry) 
HARD100DS 
Ash, black ( Fraxinus nigra ) : 0.1+8 
Ash , commercial white (Fraxinus sp . ) : .56 
Basswood, American ( Tilia glabra ) : .Jib 
Beech , American ( Fagus grandi folia ) : . 60 
Birch (B e tula sp. ) . : . Rg 
Cherry, black (Prunus serotina) : ,H? 
Cottonwood, eastern ( Populus deltoides ) : .39 
Elm , rock ( Ulmus thomasii ) : . 60 
Hickory (true hickories) ( Hicoria sp. ) : . 71 
Khaya (Khaya sp. ) ("African mahogany") : .1+2 
Mahogany, true ( Srietenia sp. ) : .1+6 
Maple , sugar ( Ac^r saccharum ) : . 60 
Oak, commercial white and red ( Que reus sp.)...: .62 
Sweetgum (Li guidambar styraciflua ) : .1+8 
Walnut , black ( Juglans nigra ) ■ -TT : .52 
Yellowpoplar ( Liriodendron tulipifera ) : .38 
CONIFERS 
Baldcypress ( Taxodium distichum ) : .1+3 
Douglas-fir ( Pseudotsuga taxifolia ) : .1+5 
Incense-cedar, California ( Libocedrus : 
decurrens ) : .32 
Pine, red ( Pinus resinos a) : .1+6 
Pine , sugar~~( pinus lambertiana ) : . 3U 
Pine , eastern white ( Pinus strobus ) : . 3U 
Pine, western white ( Pinus monticola ) : .38 
Hedcedar, western ( Thuja rlicata ) : .31 
Spruce (Picea sp. ) : .36 
White-cedar, Port Orford ( Chamaecyparis : 
lawsoniana ) : .1+0 
White-cedar, northern (Thuja occidentalis) . . . . : .29 
-3- 
1303 
