WOOD SCREWS

LIGHT GUNSMITHING

- Gil Sengel

Вehold the lowly wood screw! Its purpose and use in gun work are obvious. The principle of the spiral thread goes back a long way. Archimedes described its use as a form of edge around 250 BC. The Romans were the first to use wood screws as fasteners, with each one being hand cut. Leonardo da Vinci invented a machine that cut fairly uniform threads in the fifteenth-century. It was further perfected during the Industrial Revolution in the late 1700s.

The first spiral thread fasteners were intended for wood because the later metal screw needed a tap to cut threads into the piece of metal it was attaching to and the bolt needed manufacture of a metal nut to thread into. These threads had to fit closely. The wood screw was not bothered by such restrictions; it formed its own threads when driven in comparatively soft wood. Thus thread form, height, shape and number varied considerably.

As thin sheet metals came into use for more and more items, a form of wood screw called the self-tapping or sheet metal screw was created. The only difference between them and true wood screws is that the threads run up to the head. On wood screws, the threads stop at varying distances short of the head. Both (with proper head type) are used interchangeably in firearms.

There is also one special wood screw anyone doing woodwork on guns will eventually find useful. This is the lag screw. Designed for outdoor timber construction, its smallest size (14-inch diameter by 1 inch long) can be used to form certain large buttplate screws when fitting modified or reproduction buttplates. More on this later.