Wood machining properties of white spruce from plantation forests

The planing, shaping, boring, turning, and mortising properties of white sp ruce wood from a provenance trial and a natural stand were evaluated accord ing to the ASTM D 1666-87 standard. Wood specimens were machined at 7 perce nt moisture content using different tools, and the surface quality obtained was visually graded on a scale of 1 to 5 (excellent or defect-free to very poor). The maximum depth of tom grain produced by planing was also measure d for eight cutting conditions. White spruce wood from plantation-grown tre es Performed well for planing, shaping, and boring. However, the turning an d mortising properties of this wood were poor. For planing, a higher propor tion of defect-free pieces was obtained at a 15-degree rake angle and 20 kn ife marks per inch. At a 10-degree rake angle, the maximum depth of tom gra in even decreased but the presence of fuzzy grain increased. Machining prop erties appeared not to be significantly affected by the origin of the seed sources, including the natural forest stand. However, as a general rule, de nser wood behaved better than light wood for shaping, boring, turning, and mortising processes. Selection of best provenances for wood density, which has been shown to be strongly heritable, could indirectly help to improve w ood machining properties. Finally, high-temperature drying did not appear t o affect machining performance of this wood as compared with the convention al drying process.