Tillverkning av skruvgängor i trä med snedtyg

Abstract

There are many workbenches where the wooden screw in the vise is out of order after many years of use. To make new screws and nuts you need two tools, a screwbox to make the external threads and a tap to make the internal threads in the nut. The screwbox is a nut with internal threads where a v-shaped cutter has been placed in a precise position so that the external threads will go with the internal threads. In this essay details of great importance to obtain a well function screw are examined. Yellow birch has been used for the screws and nuts. Screwboxes with only one cutter has been examined and used. Details concerning the features of the tap have not been examined further. Ten screws of different age and eleven old screwboxes have been examined. The screwboxes have been drawn in scale 1:1. A test showing what importance the wood of the screw has to the result of the screw has been made. One old screwbox has been renovated and one has been made from pieces of birch and with a v-cutter from an old screwbox in order to detect details that affect the result of the screw.