Dating old screws

Early Cut Nails The introduction of cut nails dates from the late 16th century with the advent of water-powered 'slitting mills'.After hammering (or, from the late 17th century, rolling) the hot iron into sheets, each sheet was slit into long, square-sectioned bars by rollers which cut like a shears.Although screws were tremendously useful, the difficulty in making them prevented any widespread adoption.The earliest screws tended to be made of wood, and they were whittled by hand, with or without the help of turning on a lathe with hand-controlled turning tools (chisels, knives, gouges), as accurately as the whittler could manage.Chairs as we know them have been around since at least the 1700s.

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Later, from the Late Middle Ages until the early nineteenth century, some lathes were distinguishable as "screw-cutting lathes" because of the screw-cutting ability specially built into them.Early nails were usually square in section and the earliest were individually forged by hand from iron.The head of the nail was formed either by simply turning it over to form an L-shape or by striking a hand-held mould or 'bore' over the end of the shank to produce a shaped end such as a 'rose-head', a simple four sided pyramid shape.With the introduction of global trade laws, it became necessary to mark the country of origin.Items marked “Made in” such as “Made in England” are generally made after 1908 or so.A screw-cutting lathe is a machine (specifically, a lathe) capable of cutting very accurate screw threads via single-point screw-cutting, which is the process of guiding the linear motion of the tool bit in a precisely known ratio to the rotating motion of the workpiece.

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