Effect of Wood-based Material Type on Drilled Hole Diameter

This study examines the influence of furniture board material type on real drilled hole dimensions. Five samples were fabricated from two medium-density fibreboards (MDF), two particleboards, and plywood. Fifteen holes were drilled in the side surface of each sample using a 12 mm drill bit, a rotational speed of 3000 rpm, and a feed rate of 0.67 mm/rev. For each hole, the diameter of the cylindrical plug gauge was identified to determine whether it could be inserted freely, partially, or not at all. The results showed that in each case the effective hole diameter was smaller than the nominal drill diameter. The smallest plug gauge diameters were observed in plywood (a plug gauge with a diameter exceeding 98.8% of the drill bit diameter could not be freely inserted). Particleboards exhibited varying usable hole diameters (99.2-99.6%), while MDF showed the largest diameters of freely insertable plug gauge (99.6%). The observed differences between the plug gauge diameter and the nominal drill bit diameter can be attributed to variations in material structure. Adhesive layers in plywood and structural changes induced by drilling in particleboard likely contribute to the reduced practical hole diameter. In contrast, MDF's more uniform structure results in minimal deviations. These differences in hole diameter are crucial for the design of self-assembly furniture, as they can impact the fit and assembly process.