Document QVZ8565aa87j9vrq2KLDvYKE
Safety Engineering Tables
all other parts, including structural steel, a factor not less than 5 On hot metal cranes, however, all these safety factors should be higher, even as high as 10 throughout
For general hoisting purposes, it is not advisable for the working load of a wire to exceed % of its breaking strength This means a safety factor of 5, but factors in excess of this, and varying up to 8 or more, are often required for safe and economical operation
Cast iron flywheels should have a safety factor of 10, but those made of wood should have the factor of safety raised to 20
Other data
In addition to data on construction materials, information is supplied on lighting and ven tilation. chemicals and contaminants, mathe matical functions and conversion factors, and abbreviations used in this Manual
TABLE 47-B BASIC STRESSES FOR LAMINATED STRUCTURAL MEMBERS
Extreme jiber
in bendtng or tension parallel
to gram (psi)
Maximum longi tudinal shear
(pst)
Compression perpen
dicular to
gram (pst)
Compression parallel to grain
(pst)
Modulus of elasticity in bending (IJ000 psi)
Baldcypress (southern cypress)
Cedars Redcedar. western White-cedar Atlantic (southern white cedar) and northern White-cedar Port-Orford Yellow-cedar Alaska (Alaska-cedar)
Douglas-fir. coast type Douglas-fir. coast type.
close-grained Douglas-fir. Rocky Mountain type Douglas-fir, all regions, dense Fir, balsam Fir California red, grand, noble
and white Hemlock, eastern Hemlock, western
(west coast hemlock) Larch, western Pine eastern white (northern
(white) ponderosa, sugar, and western white (Idaho white)
Pine |ack Pine lodgepole Pine red (Norway pine) Pine, southern yellow Pine southern yellow, dense
Redwood Redwood, close-grained Spruce, Engelmann Spruce, red, white, and Sitka Tamarack
SOFTWOODS
2.400 1,600
170 135
1,400 2000
2,000 2,750
2,950 2,000 3,200 1,600
2.000 2,000
2,400 2 750
115 150
150 150
150 135 150 115
115 115
125 150
1,600 2,000 1.600 2,000 2,750 3200 2,200 2,400 1,400 2 000
2,200
135 135 100
135 180 180
115 115 115 135 160
330
220
195 275
275 350
375 310 410 165
330 330
330 350
275 240 240 240 350 410 275 295 195 275 330
2.000
1,300
1,050 1,650
1 450 2.000
2,150 1,450 2,350 1300
1,300 1,300
1,650 2.000
1 400 1,450 1 300 1,450 2,000 2350 1,850 2,000 1,100 1,450 1,850
1300
1,100
900 1,600
1300 1 800
1,800 1300 1300 1,100
1 200 1300
1300 1300
1 100 1300 1 too 1300 1 BOO 1,300 1,300 1300 1 100 1 300 1,400
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