Information concerning the relative magnitudes of shear strength as determined by using cube-shaped or notched specimens in roller or nonroller testing apparatus has often been contradictory. This describes a comparative study, conducted at the U.S. Forest Products Laboratory and the Australian C.S.I.R.O. Division of Forest Products on six different specimen-apparatus combinations using matched specimens of southern yellow pine and overcup oak.nSeveral of the combinations yielded estimates of shear strength that were significantly different, but standard deviations of shear strength were generally independent of the test method. Significant interaction of growth ring orientation and test type was apparent and may have contributed to previous conflicting views. In general, cube specimens yielded higher estimates of shear strength than notched specimens, and nonroller apparatus yielded higher estimates than roller-equipped apparatus.
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