Rivet

“ It is usual to have the rivet holes one-sixteenth of an inch in diameter larger than the rivets, in order to allow for their expansion when hot; it is evident, however, that the difference between the diameters of the rivet hole and of the rivet should vary with the size of the rivet.
The hole in the die is made larger than the punch; for ordinary work the proportion of their respective diameters varies from 1:1.5 to 1:2. ”

“ The best way is to bore straight through both pieces and insert the rivet. In some cases the rivet is headed up in the bore and again washers are used and the heading effected on the washer. Copper rivets are soft and easily handled, but are costly as compared with iron rivets.
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Good prices are obtained for the guards for open fireplaces made in many varieties in these days. The return of the open fireplace in modern houses has created a demand for these guards and in Fig. 10 we show a design for one of them. The posts are made sufficiently stiff by uniting two sides with rivets. ”

“ May I urge upon shipbuilders the importance of endeavouring to extend the application of power riveting to the shell plating of iron vessels. By this means we shall both increase the frictional resistance, and also, by more completely filling the rivet holes, vastly improve the rigidity of the riveted joints. ”

“ If the rivet is driven into a hole that has been punched with a sharp punch and sharp die, the result is that the fillet is cut off under the head, and the riveted end is also cut, and does not give the clinch or hold desired. ”

“ They are again heated, the jaws shaped, and a hole punched in each jaw for the reception of the rivet. They are again heated and rehammered to make the shanks round, and shape the knob at each end. While cold, they are fastened together by a rivet, which is itself hammered out of a rod, the rivet being heated and clinched after it is inserted. ”

“ I claim, 1st, the arrangement or combination, substantially as hereinbefore described, and illustrated in the accompanying drawings, of the vertical dies, b b, for cutting off and carrying the cut-off length of rod, and for shaping the head of the rivet or bolt, with the horizontal punch or die, m, for shaping the shank of the rivet or bolt, and upsetting the end of the rivet or bolt into a head in the vertical dies. ”

“ The author has studied the particulars of a number of cases to ascertain under what conditions as to stress, having due regard to the effects of vibration, rivets will remain tight, or become loose. Every loose rivet that may be found cannot, of course, be taken as being due to excessive stress; the more frequent cause is indifferent work, evidenced by the fact that neighbouring rivets will frequently be found quite sound, though the failure of some will cause a greater stress upon the remainder. ”

“ Loose rivets and want of tightness in other [109] parts of the work may frequently be detected at sight by a reddish bloom which appears on the neighbouring surfaces, caused by rust working out and spreading under the effects of weather; it may be seen round rivet-heads or along the edges of angle-bars, or other parts where there is movement. Loose rivets, though generally to be detected also by the hammer, may perhaps in the case of thin-webbed cross-girders be working in the web-thickness only, possibly to a considerable extent. ”

“ The quality of the work done is superior to hand work, chiefly in that when rivets are well heated the pressure is equalised, and affects the rivets throughout their entire length, filling the holes to their utmost. [144] This advantage tells more in the case of keel riveting, and that it is so is evidenced by the fact, as communicated by a foreman having great experience, that rivets 1⁄4-inch longer than rivets closed by hand have even less superfluous surface material when closed by the machine. ”

“ For reverse stresses it is advisable to keep the shear stress in any rivet so low, say 3 tons per square inch, that the frictional resistance of the parts gripped by the rivets shall be sufficient to prevent any tendency to slip under the influence of the smaller of the two forces to which the part is liable, to insure that, if brought to a bearing in one direction by the greater force, it shall not go back with reversal of stress. ”

“ Rivets.—Rivets of steel or iron should be made in solid dies. Rivets made in open dies are liable to have a fin on the shank, which prevents a close fit into the holes of the plates. The use of solid dies in forming the rivet insures a round shank, and an accurate fit in a round hole. In addition, there is secured by the use of solid dies, a strong, clean fillet under the head, the point where strength is most needed. ”

“ Heat thoroughly the end of a 3⁄8-inch rivet, 13⁄4 inches long, and with it rivet the two portions tightly together. Heat the tongs, make them work freely, and adjust them to hold 3⁄8-inch flat iron, with the entire length of the jaws in contact and with the ends of the handles 1 inch apart. The jaws and handles should be adjusted so that a line extended lengthwise across the center of the rivet would pass midway between them.
93. Light Chain Tongs.—Fig. 75. Forging, swaging, punching, fullering, and riveting. Material: 13 inches of 3⁄4-inch square mild steel. ”

“ The rivets are usually made with a flat or rounded head attached to a short cylindrical shaft or shank. A hole is punched through each piece of metal to be joined. The pieces of metal are placed together so that the holes are in line and a rivet shank slipped through these holes. The head of the rivet is then rested on a flat iron or steel anvil and the headless end is hammered over until it forms into a second head and thus holds the two pieces of metal tightly together.
The pail offers a very simple problem in riveting [101] and it is very easy to make a substantial pail from a tin can. ”

“ The example shown in Fig. 245 is in my own collection. I do not, however, know in what part of Ireland it was found. The rivet-hole is at the side, and not on the face, in which, however, there is a slight flaw, which assumes the appearance of a hole in the figure. In Canon Greenwell’s collection is a nearly similar specimen (103⁄4 inches) , found at Balteragh, Co. Derry, with two rivet-holes at the side and the socket somewhat ornamented by parallel grooves at the mouth and at the junction with the blade.
[208]
Fig. ”

“ Thus the enormous force of men and the fearful clatter formerly displayed in these huge works where the riveting of boilers was carried on can now be dispensed with, and in place of the noisy hammer with its ceaseless blows has come the steam or the hydraulic riveting machine, which noiselessly drives the rivet through any thickness of metal, clinches the same, and smooths the jointed plate. ”

“ Commencing with a countersunk head as the strongest form of head, the greater the fillet permissible under the head of a rivet, or bolt, the greater the strength and the decrease in liability to fracture, as a fillet is the life of the rivet. ”

“ It is fascinating to watch the end of the rivet flattening under the chattering blows of the gun. An expert riveting team can drive several hundred rivets a day, and when paid on piecework the team gets six and one-half cents per rivet. This is divided among the team, usually in the proportion of 40 per cent to the riveter, 30 per cent to the backer-up and 15 per cent each to heater and passer. Many expert riveters earn as much as $60 a week. ”

“ Better than all, perhaps, when bars and tubes and angle pieces are being built into a framework rivet holes can be punched with the simplest pneumatic tool, while the joins and the rivets can be instantly and securely welded together with an electric heating iron. ”

“ It is hard to tell what is superior and what is subordinate work. I suppose that in a steam engine the smallest rivet is quite as essential as the huge piston, and that if the rivet drops out the piston-rod is very likely to stop rising and falling. ”

“ In setting these small rivets, it is absolutely necessary that they closely fit the holes, as at A, otherwise the result will be as indicated at B in the sketch. Be careful not to leave too great a length for rounding over on the metal. This extra length should approximately equal the diameter of the rivet and must be filed flat on the top before riveting. In case of pins, it will be found easier to cut them off to the proper length after they are inserted. Use the smallest hammer available, striking many light blows rather than a few heavy ones. ”

“ This alters the throat radius somewhat but this fact is generally neglected. In blow pipe systems the work must be exactly to measurements. Laps for riveting are, therefore, added as shown in Fig. 89. It should be noted that the rivet holes for the longitudinal seams are on the circumference lines of the pattern, while those for the transverse seams are in the center of the lap. The rivet holes are equally spaced and as the lap is 3⁄4 in. wide, the centers of the holes are 3⁄8 in. in from the edge of the lap, and 3⁄8 in. in from the miter cut of the adjoining piece of the elbow. ”

“ The riveting of the frames and beams is the simplest of all the work overtaken by the hydraulic riveters, and it is here the system is seen to most advantage. In any yard furnished with these machines rivets are closed at a greatly accelerated rate compared with work done by hand. Tweddell machines have been known to close, in beams, 1,800 to 1,900 rivets per machine per day of 91⁄2 hours. In frames the average rate at which rivets are closed is about 1,400 per day. ”

“ Open Die Rivet.
If rivets are made of steel they must be low in carbon, otherwise they will harden by chilling when the hot rivets are placed in the cold plates. Therefore, the steel must be particularly a low grade or mild steel. The material should show a tensile strength not greater than 54,000 pounds per square inch and an elongation in eight inches of thirty per cent. The United States government requirements are that steel rivets shall flatten out cold under the hammer to the thickness of one-half their diameter without showing cracks or flaws ”

“ Hydraulic riveting has demonstrated not only that the work could be as well done without a blow, but that it could be better done without a blow, and that the riveted material was stronger when so secured than when subjected to the more severe treatment under impact. ”

“ The sleepers are riveted cold. The rivets are of soft steel, and the pressure with which this riveting is effected is so intense that the sleepers cannot be separated from the rails, even after cutting off both heads of the rivets, unless by heavy blows of the hammer, the rivets being driven so thoroughly into the holes made in the rails and sleepers that they fill them up completely. ”

“ In whatever way it is accomplished, I look to the use of machine riveting as one very great step in advance in the future improvement of the riveted joints of iron ships; and if the weight of iron vessels is to be reduced in any important degree, or if the dimensions and proportions of large merchant steamers are to increase in the future as they have done in the past, I feel sure that one of the first steps must be the reconsideration of our butt fastenings. ”

“ It is his duty to hot the rivets in the forge for his mates and to perform sundry other small offices, such as fetching water from the tap in the shed, or holding a nail bag in front of the rivet head which is being cut away, in order to keep it from flying and causing injury to any of the workmen. The forges for hotting the rivets are fixtures and are supplied with air through pipes laid beneath the ground from the fan under the wall. Several boys [76] usually work from one fire, and there is often a scramble for the most advantageous position in the coals. ”

“ A good arrangement for supplementary bracing between plate-girders, which gives little trouble in carrying out, is shown in Fig. 67; or where the stiffeners of such girders [118] are in line across the bridge, the detail given in Fig. 68 may involve less expenditure. Difficulties may be experienced in riveting, unless great care is taken in the positioning of rivets. Fitting-bolts are only to be relied upon as such, if they really justify the name; they are, though easy to specify, by no means easy to secure under the conditions of practical work. ”

“ If however, we are prepared to sacrifice a fair appearance to utilitarian simplicity, there seems no sufficient reason why, above water, all the rivets should not be closed up with snap heads and points, both inside and outside. ”

“ With the [140] same number of men the work is accomplished in something like one-third of the time. The modus operandi in overtaking this feature of the work may be briefly described. For the riveting of the frames, in almost every case, two cranes of any convenient construction are fixed at the head of the berth in [141] which the vessel is to be built; the frames are laid across the keel as in hand work, and rest on trestles, where the portable riveter, carried on the before-mentioned cranes, rivets them up. ”

“ Hammered riveting is much more expensive than machine or snapped riveting, and has a tendency to crystallize the iron in the rivets, causing brittleness.
In the present state of the arts all the best machine riveters do their work by pressure, and not by impact or blow. ”

“ The Leviathan is essentially an iron ship, more completely so perhaps than any vessel hitherto built. Iron plates, angle irons, and iron rivets form the sinews, muscles, and bones of this monster of the age of iron. The plates vary in thickness from half an inch to an inch; the rivets are about an inch in diameter, and it is these that hold the vast fabric together. ”