Timbers – 5" and larger

5x8

Standard: DOC PS 20 / NDS SupplementSource: Nominal − ½" (green), calculated
xyb = 4.5d = 7.5
Cross-section, to scaledimensions in inches

Dimensions

Depthd
7.5in
Widthb
4.5in

Mass and area

Cross-sectional areaA
33.75in²
Outside perimeterP
24in

Strong axis x–x

Moment of inertiaIx
158.2in⁴
Elastic section modulusSx
42.19in³
Plastic section modulusZx
63.28in³
Radius of gyrationrx
2.165in

Weak axis y–y

Moment of inertiaIy
56.95in⁴
Elastic section modulusSy
25.31in³
Plastic section modulusZy
37.97in³
Radius of gyrationry
1.299in

Torsion and stability

Torsional constantJ
142.6in⁴

Equivalents in other standards