Measuring Grain Angle

Abstract

In this chapter the term grain angle will be used from time to time to refer to deviations other than those due to spiral grain or its related phenomena of interlocked and wavy grain. Sloping grain in sawn timber, commonly called cross grain (Anderson et al. 1945), can arise in many ways. Grain deviations around knots and other defects are an obvious source, as are all types of stem kinks including spiral bole and nodal or other stem swellings. In addition, grain will run across sawn timber if the cutting pattern is not parallel to the growth layers. Spiral grain itself affects grain angles only in the tangential plane relative to the stem axis. For practical purposes it may be of little consequence how grain deviations arise, but it is often important to be able to measure cross grain as the result of any or all of these sources (Boas 1933, Anderson et al. 1945, Koehler 1955).