Visual stress rating using strength ratios is the only expedient and currently available method of assigning strength design values to pallet shook. In this study, the estimated bending strength ratio (ESR), determined from ASTM D245, and the actual bending strength ratio (ASR), determined through testing were compared for over two thousand two hundred pieces of eastern oak pallet lumber. The ESR generally underestimated the ASR for stringers and deckboards with knots and slope of grain. The ESR increasingly underpredicted the ASR as knot size increased. The ESR consistently underpredicted the ASR throughout the range of severity of slope of grain. If assigners of design stressed for pallet shook use ASTM strength ratios, then conservative strength estimates will result; this is particularly true for low quality material.