Multiply               Multiply
Depth of   Camber      Depth of   Camber
Truss.      by         Truss.      by

1-4 span 2.00 1-12 span .666 1-5 " 1.60 1-13 " .614 1-6 " 1.33 1-14 " .571 1-7 " 1.15 1-15 " .533 1-8 " 1.00 1-16 " .500 1-9 " .888 1-17 " .470 1-10 " .800 1-18 " .444 1-11 " .727 1-20 " .400

TABLE OF AMERICAN WOODS.

Weight per Resistance in lbs. per
Kind. cubic foot square inch.  Value of s.
in pounds.  Extension Compression.

White Pine.          26         12,000       6000          1229
Yellow Pine.         31         12,000       6000          1185
Pitch Pine.          46         12,000       6000          1727
Red Pine.            35         12,000       6000          1527
Virginia Pine.       37         12,000       6000          1456
Spruce.              48         12,000       6000          1036
Tamarack.            26         12,000       6000           907
Canada Balsam.       34         12,000       6000          1123
White Oak.           48         15,000       7500          1743
Red Oak.             41         15,000       7600          1687
Birch.               44         15,000       7000          1928
Ash.                 38         16,000       8100          1795
Hickory.             51         15,000       7200          2129
Elm.                 45         16,000       8011          1970

The above table is compiled from a much fuller one in Vose’s Treatise on R.R.  Construction.

TABLE OF BOLTS AND NUTS CALCULATED FOR A
WORKING STRAIN OF 15,000 LBS.  PER
SQUARE INCH OF SECTION.

Diameter.   Area.     Strength in Weight per           Thick’s  No. thr’s
Inches.   Sq. inches.   Pounds      Foot.   Square nut.  of nut. per inch.

1/2      .19635        2940     0.66     1-1/4 in    3/4 in    12
5/8      .30680        4602     1.03     1-3/8       3/4       10
3/4      .44179        6630     1.49     1-1/2       7/8       10
7/8      .60132        9019     2.03     1-3/4     1            9
1          .78540       11775     2.65     2         1            8
1-1/8      .99402       14910     3.36     2         1-1/8        7
1-1/4     1.2272        18405     4.17     2-1/4     1-1/4        7
1-3/8     1.4849        22260     5.02     2-1/2     1-3/8        6
1-1/2     1.7671        25505     5.97     2-3/4     1-1/2        6
1-5/8     2.0739        31095     7.01     2-7/8     1-5/8        5
1-3/4     2.4053        36075     8.13     3         1-3/4        5
1-7/8     2.7612        41415     9.33     3-1/4     1-7/8        4-1/2
2         3.1416        47130    10.62     3-1/2     2            4-1/2
2-1/8     3.5166        53190    12.00     3-3/4     2-1/8        4
2-1/4     3.9761        59640    13.40     4         2-1/4        4