sitka spruce: uses, growth, management. 
37 
Table 16. — Average diameter outside hark at 15 feet above ground of Sitka 
spruce on all sites in different parts of Oregon and Washington — Continued. 
Age. 
Tsiltcoos. 
Newport. 
°-*-| SSL 
Hoquiam. 
Beaver. 
Average. 
Diameter in inches outside bark at 15 feet. 
Years — Continued . 
310 . 
53.8 
54.8 
55.7 
56.7 
57.5 
51.4 ! 60.5 
52.4 61.7 
53.5 1 62.8 
54.5 
54.4 
55.8 
57.2 
58.6 
60.0 
61.4 
55.3 
320 
.56.6 
330 . 
57.8 
340 . 
59.0 
350 .. 
65.1 
66.2 
60.2 
360... 

61.4 
370 

67.3 62.8 
62.5 
380. . 
68.4 
69.6 
63.6 
390 . 
64.7 
400 
65.8 
410. .. 
".";;;:::: : 
67.2 
95 ! 78 
100 
133 73 
78 
Table 17. — Results of tests on Sitka spruce wood from Washington, in green 
and air-dry condition, in the form of small clear pieces. 1 
[From Table 1, U. S. Dept. Agr. Bull. 556.] 
Mechanical property. 
Green 
condi- 
tion. 
9 
24 
53 
.37 
33 
4.5 
7.4 
3. 000 
5,500 
1,180 
6.4 
2,600 
330 
780 
230 
370 
Air-dry 
condi- 
tion. 
Number of rings per inch 
9 
24 
Moisture content (per cent ) 
8.9 
Specific gravity, based on volume and weight when oven-dry 
.38 
26 
Shrinkage from green to oven-dry condition: 
Radial (per cent) 
Tangential (per cent) 
Static bending: 
Fiber stress at elastic limit (pounds per square inch) 
7,200 
11,200 
Modulus of elasticity (1,000 pounds per square inch) 
1,610 
10.4 
Compression parallel to grain: 
5,770 
Compression perpendicular to grain: 
1,010 
Shearing strength parallel to grain (pounds per square inch) 
1,210 
Tension perpendicular to grain (pounds per square inch) 
Hardness, side: 
Load required to embed 0.444-inch ball to one-half its diameter (pounds) 
530 
1 Test specimens were 2 inches by 2 inches in section. Bending specimens were cut 30 inches long; others 
were shorter, depending on test. 
» Work to maximum load represents the shock-absorbing ability of the wood. 
LUMBER GRADES. 
The following lumber grades are in use for different Sitka spruce 
products : 17 
Finish : B and Better. 
Flooring: B and Better. 
Ceiling: B and Better. 
Stepping: B and Better. 
Battens: B and Better. 
Partition: B and Better. 
Bevel siding: A, B, C. 
Wagon-box sets : B and Better. 
Boards and strips: Selected Common, 
No. 1 Common. 
17 For further information, see West Coast Lumberman's Association, " Rule 2 : Stand- 
ard Classification, Grading, and Dressing Rules for Douglas Fir, Sitka Spruce, Cedar, 
and Western Hemlock Products," January 22, 1922. 
