The influence of some cutting bill variables on hardwood dimension stock yields

Many furniture and dimension manufacturers use yield charts such as those developed by the U. S. Forest Service for estimating dimension stock yields. In this study, actual yields from Number 1 and Number 2 Common red oak, sampled from three dimension manufacturers, were found to deviate from the yield values predicted from Forest Service charts. Since these chart values are described as being maximum yields, most actual yields sampled fell below the maximum potential yield.A correlation analysis showed that the sampled yield deviations in Number 1 Common were inversely proportional to the maximum cutting length divided by the range of lengths. Yield deviations in Number 2 Common were also analyzed, but were not found to be significantly correlated with any cutting bill variable tested.A regression analysis showed that as much as 47% of the variation in yield deviations, in Number 1 Common, was explained by the maximum cutting length divided by the range of lengths. Furthermore, over one-half of the variation in yield deviations was explained by this cutting bill variable when cutting bills containing maximum lengths greater than 70 inches were excluded from the sample.It is believed that as the maximum cutting length and/or range of lengths increase, saw operator(s) efficiency declines. One hypothesis is that the arrangement or "batching" of dimension stock, in a cutting bill, does affect the chances of obtaining the maximum potential yields given by the Forest Service yield charts.