EFFECT OF NUMBER OF FASTENERS ON THE STRENGTH OF CORNER JOINTS FOR CASES

Tests were carried out in order to determine the bending strength of 4 57-mm-(18-in.-) wide case joints constructed with multiple fasteners. Both dowels and screws were included in the tests. Results indicated t hat bending strengths increase rapidly until the ''zones of influence' ' of the fasteners overlap. No increase in strength was obtained beyon d that point. Screw length was found to have a greater effect on stren gth than diameter. In the case of dowel joints, it was found that beca use of the adhesive added to the joint area, joints could be construct ed that exceeded the bending strength of the board itself.