Wood screw design: influence of thread parameters on the withdrawal capacity

Abstract Self-tapping wood screws are important fasteners in timber construction. A characteristic of these is their high axial load-bearing capacity, which also depends on withdrawal capacity. This used for structural design and thus an optimization parameter screws. To increase the knowledge influence thread parameters, such as outer diameter, pitch or flank angle, required. The influences angle capacity have not yet been sufficiently subjected to research therefore investigated this study. total ten specially developed screw prototypes with pitches range 3.04 mm 5.9 angles 35° 45° used. flat ribbed bars uncoiled thread. effect measured using experimental setup based test standard EN 1382:2016. showed a significant (p = 0.000, f 0.37) whereas was 0.283). smaller leads higher irrespective angle. results explained theoretical models bonding mechanisms conical stress distribution. optimize ø 8 screw, preferable. determined can be improve accuracies calculation