A sewing machine needle consists of:
shank - clamped by the sewing machine's needle holder
shoulder - where the thick shank tapers down to the shaft
shaft - a length suitable for driving the eye and thread through the material and down to the bobbin
groove - cut in the back of the shaft to release the thread into a loop that aids the hook or shuttle to pick up the thread
scarf - provides extra room for the hook or shuttle to pass close by
eye - carries the thread
point - penetrates the material by either parting the threads or cutting a hole in the fabric
Sizes codes
More than twelve conventions exist for numbering the sizes of sewing machine needles, though only two remain in common use: the American (established and propagated by Singer) and the European (also called the "number metric" or "NM"). The European designation, established in 1942, is considered the uniform fixed size and corresponds to the diameter of the needle in hundredths of a millimeter at a non-reinforced point above the scarf.
from Wikipedia
EARLY PATENTS RELATING TO NEEDLES
Historical details are wanting as to the invention and progress of the needle manufacture. Needles made of bone seem to have been in use from the earliest stages of prehistoric man. The high estimation in which needlework was held by the Hebrews and their contemporaries shows that needles must have been in every-day use at that time. In our country their manufacture was introduced about the middle of the sixteenth century; the secret of their production seems, however, to have died with the foreigner who introduced the industry into this kingdom. In the days of Queen Elizabeth, a German reintroduced the manufacture and about 1650 needle manufactories were established at Long Credon, near Redditch, the latter district remaining even to this day the head-quarters of the English needle manufacture. This particular industry never owed much to patents, and there are consequently comparatively few entries relating to the subject.
The first that we come across was granted in 1755 to Weisenthal, a merchant carrying on business in London, for a double-pointed needle, the eye being in the centre, thus avoiding the necessity of turning the needle in doing embroidery work. This could hardly have been a new idea even then, and it has been patented about; half a dozen times since. Weisenthal's patent was, however, only for a new form of needle, without any reference to the mode of manufacture.
The earliest grant of the latter kind is dated 1775, and is in the name of William Sheward, of Redditch, worsted needle manufacturer, for needles with eyes upon a new and particular construction. The needles being eyed and guttered, the inventor brings them in contact with a small steel tool, drill, or rimer, carried in a lathe. The tool is kept revolving and the eyes of the needles are then put upon or to the point of the said drill or rimer, in such manner and form, and continue there so long till the said tool, drill or rimer hath worked in and about the eye of the needle, so as to take off and smooth all the edges from the eyes of such needles. Here we have the first attempt at making drill-eyed needles an expression which does not, however, denote that the eyes are actually drilled out of the solid. It was stated that a Studley needle-maker introduced this method in 1793; but, as might have been expected, it failed, on account of the expense. Sheward seems to have subsequently removed to Birmingham, for in 1789 he had a patent, in which he is described as of that town, for a new and improved method of finishing the eye of a needle in a way superior to any yet invented. His invention consisted in arranging upon a revolving shaft a number of steel discs, alternately roughed and smoothed, the former being larger in diameter than the latter. The needles being applied to the rough discs were rendered free from the square edges that punches always leave in the eye of a needle, and the small wheels wall burnish or polish the cheeks and full parts about the heads and turn them off complete. The only information we have been able to gather respecting Sheward is that he at one time occupied a farm at Beoley near Redditch, and that he was also the inventor of a particular form of horizontal windmill, the sails of which were inside a hollow drum. This was an idea which found particular favour during the last century.
The next patent to be noticed is that granted in 1795 to William Bell, of Walsall, for making all sorts of needles, bodkins, knitting-pins, fish-hooks, netting-needles, mesh-pins, and sail-needles. The method consisted in casting the articles in sand moulds, the metal used being partly refined by melting with charcoal-dust and lime or common salt, the mixture being frequently stirred with an iron rod. The inventor states that articles cast in this manner are capable of being tempered and hardened or softened in the usual way.
However suitable the process may have been to the production of bodkins and such-like articles, it would be totally inapplicable in the case of the finer kinds of needles.
In 1812, John Scambler, a needle-maker, of Birmingham introduced the Patent Golden Needles, the chief peculiarity of which was that the eyes were gilt by being dipped in a solution of gold in aqua regia, a process which at best would give but a very unsatisfactory result. The needle had also a long point, the taper part commencing at about two-thirds the distance from the extremity. The eyes were square or round, instead of oval, and the needles were hardened by immersing in oil and water. It is often asserted that the needle-pointing machine is of German invention, but that is an entire mistake. The invention is English, and the error may have arisen from the fact that needle-pointing machinery was first used in a German manufactory, the unreasoning opposition of the workmen preventing its introduction here for many years. Pointing by hand is, however, now almost entirely obsolete at Redditch, foreign competition having compelled manufacturers to adopt the machine. The needle-pointing machine is much older than is generally supposed, the original patent having been granted in 1833, nearly half a century ago, to Daniel Ledsam and William Jones, of Birmingham. The machine in question not only grinds the points of needles, but it cuts off the wire, the lengths being sufficient for two needles. The end of the wire, which is coiled on a drum, is passed through a set of straightening pegs, and then seized by a pair of pliers, which draw off a determinable length of wire from the coil. The amount thus drawn off at each pull of the pliers is governed by a crank and slotted aim, the bearings of which may be altered according to the " throw " required. The wire is then severed by means of a sliding cutter, and the part cut off held in a tube. Adjacent to the end of the tube there is a wheel with grooves in the periphery, each capable of holding a single needle. When a fresh length of wire is cut it pushes that previously severed, and which has been described as remaining in the guide tube, on to the groove in the wheel, the face of which is not broad enough to take the whole length of the needle, so that the ends overhang. A bar, bent to the curve of the wheel, keeps the needles from falling out of the grooves as the wheel revolves, and also serves to impart a rotatory movement to each needle by the friction between the wheel and bar, the friction being increased by covering both with wash-leather. In this position they are presented by the continued revolution of the wheel to the grindstone, which is hollowed out to correspond to the curvature of the former. A projecting guard-plate gently depresses the needles lo bring the points in more certain contact with the stone. The grindstones, which are driven independently, and have special modes of adjustment, are two in number, one on either side of the wheel, so that both ends of the wire are sharpened. When the operation is complete the eyes are punched out, and the needles are finished in the usual way. We are not aware whether Ledsam and Jones's machine was ever used, but its main features have been reproduced in that now generally employed, which is, however, not entirely self-acting, the rotation of the wires being imparted by the fingers of the grinder.
A most important invention was patented in 1839 by Abel Morrall, a Studley needle-maker, for burnishing the eyes of needles by threading them upon a roughened steel wire stretched in a frame and caused to revolve, or to move backwards and forwards. The needles are thus made to vibrate upon the wire in every direction and the eyes effectually cleared from all roughness. This very valuable patent was shortly afterwards purchased by Messrs. Bartleet & Sons, of Redditch and the use of string or cord, which the inventor thought might also serve as well as wire, was disclaimed by them in 1841. An attempt was made by a league of twelve rival manufacturers to set the patent aside by a scire facias, but the proceedings were unsuccessful and the patent was held to be valid. The effect of the introduction by Messrs. Bartleet & Sons of the oval-eyed needles perfected by this machine has doubtless been to cause the eyes of needles generally to be made larger than they formerly were, to the great convenience of the majority of persons who use them. Up to that time there were no means of making the eyes perfectly smooth, except in the case of round eyed needles, and even they were benefited by the use of the burnishing machine. But it is still a question if any needle is so good in use as one with a perfect round eye, carefully drilled and then burnished by the best method known in the trade.
In 1841(1840), Luke Herbert, a consulting engineer and patent agent, then residing in Birmingham, took out a patent for a machine which was a palpable imitation of Morrall's. Herbert proposed to string the needles on a roughed wire, as in the former machine, but the needles were to be firmly held in clamp whilst the wire was drawn backwards and forwards through the eyes. The plan failed in practice, as might have been foretold, for it did not produce the right kind of action upon the eye.
from the Sewing Machine Gazette
Needles
A pointed instrument for carrying a thread through a fabric, leather, or paper. It usually passes through the fabric and drags the thread after it, but it is otherwise with eye-pointed needles, such as packing-needles, and those in sewing-machines. The last-mentioned are really awls.
Needles of bone are found in the caves occupied by the ancient inhabitants of France during the stone period, and the same material is in use among uncivilized tribes at the present day. The needles of ancient Egypt, as described by Wilkinson, are of bronze, and no eye is apparent in his illustration of them. It would rather seem that the thread is attached to a circular depression near the blunt end. It would lie hardly reasonable to doubt that they had needles with eyes. We know from Scripture and secular history and from the tape-try that has survived thirty centuries that they were skillful and painstaking seamstresses. “A woman must not go out on the Sabbath with a needle that has an eye." Mishna. The Phrygians and Hebrews held fine needlework in high estimation. Needles of bronze were used by the Greeks and Romans, are described by Pliny, and have been found in Herculaneum.
The history of art progress during the Middle Ages is a blank, but we find that needles were manufactured at Nuremberg in 1370. The history of their manufacture in England is involved in doubt, but it is said to have been introduced about 1543- 45, either by a Spanish negro or a native of India, who died without disclosing the secret of his process. It was recovered during the reign of Elizabeth, by Growse, a German.
In 1650, Christopher Greening and a Mr. Damer established needle-factories at Long Crendon , near Redditch, and were soon followed by other needle-makers from London. Redditch is yet the great centre of the English needle manufacture. The earliest needles were "square-eyed," that shape being most readily produced. "Drill-eyed" needles, after many unsuccessful attempts, were first brought out in 1826. The burnishing machine, in which the needles are strung on a steel wire to which rapid revolution is imparted, was introduced two years later. By this, a beautiful finish is imparted to the eye. The process of hardening them in oil was introduced in 1840, water having been previously used for this purpose, which caused a large proportion of them to become crooked, requiring the services of a large number of workmen to straighten them. These being thrown out of employment by the new process made a riot and drove its introducer out of town, but it was finally generally adopted.A similar disturbance had taken place in 1830, on the introduction of the stamping-machine. The machine for pointing is of still more recent introduction.
A needle with a point at each end and an eye at the middle of its length was patented in England in the year 1755, for hand-sewing or embroidering, the patentee describing it as used by holding it with the fingers at the middle of its length, so that it will not require turning. In 1829 it was successfully introduced into an embroidering machine, which is still in extensive use. As many as one hundred and thirty such needles, worked by pincers on opposite sides of the fabric to be embroidered, are used in a single machine.
In 1812 a sewing machine inventor adopted the same kind of needle and some others have made sewing-machines with such needles, but no such machines have ever been successful. The accompanying cut shows a number of patented needles, some with eyes near their points, some having means of slipping the thread into the eye without reeving. Needles are known as sharps, betweens, blunts, according to the relative fineness of their points. The so-called golden-eyed needles are tinted by dipping in an ethereal solution of gold. The silver-eyed needles are not really silvered, but the silvery hue is given by a peculiar polish. The blue-pointing is a dark polish effected by applying the needles to a revolving stone of a bluish color. The drilled-eyed needles have the eyes finished by a countersink drill, the eye end being previously softened.
Bell's needles, English patent, are made of steel, cast in sand molds. The mode is particularly intended for bodkins, fish-hooks, knitting, netting, packing, and sail needles.
by Knight's American mechanical dictionary