CHAPTER IIIPractice Exercises

Fig. 32.—Drawing with the Swages.

Fig. 33.—Drawing with the Flatter.

Drawing with the top and bottom fullers, in the manner shown with the swages (Fig. 32), ought to be done cautiously,as the metal decreases in size so rapidly that there is danger of its becoming too small at the fullered place before the operator is aware of it. When using the top fuller alone, in the same manner as the flatter (Fig. 33), similar precautions should be observed. If the metal is to be decreased between two shoulders, the top fuller may be used to rough it out; but the fuller marks should be distributed between the shoulders, until one of the set hammers or the flatter can be used.

If the metal is being drawn and is held crosswise on the anvil, as shown ata,Fig. 34, it will increase in length more rapidly than it will in width, and if held lengthwise as atb, it will increase more in width than in length. This is due to the fact that the anvil is slightly convex on its face, so that it has the effect of a large fuller.

Fig. 34.—Drawing with the Hand Hammer.

The most difficult drawing for the beginner is to form metal into a square or hexagonal shape. To draw it into a square form, the metal must always be turned either one quarter or one half of a revolution to prevent its becoming diamond-shaped, and the blows must bedelivered equally on the four sides to prevent its becoming oblong. If it does become diamond-shaped, it can be made square by delivering blows at a slight angle on the corners and sides of its long diagonal as shown atA,B, andC,Fig. 35. If it is but slightly diamond-shaped, the method shown atBwill prove satisfactory, but if badly out of square, the method atAwill be the best.

Fig. 35.—Squaring up a Diamond-shaped Piece.

In drawing the hexagonal form, the metal should be turned by sixths of a revolution. If it becomes distorted, it may be forged with such blows as are shown atBandC; if held as atA, it would be marred by the edgee.

54. Bendingis the operation of deflecting metal from a straight line or changing its form by increasing the deflection already present. Iron of any cross-sectional shape can be bent, but some shapes are much more difficult than others.

The easiest to bend is the round, the only difficulty beingto prevent the hammer blows from showing. If the metal is to be round in section when finished, the work will not have a good appearance if the cross section is oval at some places and round at others, and unless the hammer blows are cautiously delivered this will be the result.

Bending metal of a square section at right angles with the sides is not very difficult, but bending such a section in line with the diagonal is quite difficult, because the edges are liable to be marred where they rest on the anvil and where the blows are delivered. The best method of making bends of this kind is to heat the metal only where the bend is to be, and then to bend it by pressure or pulling, while the work is held securely in the vise, hardy hole, or swage block. If the heating cannot be confined to the desired space, all excessively heated parts should be cooled.

Oval sections are easily bent through their short diameters, but in bending through the long diameters, the same method should be pursued as described above for bending the square section in the plane of its diagonal. Further explanations for bending are given on pages118-121.

55. Upsettingis the operation of enlarging metal at some desired point or place. It is done by hammering, ramming, or jarring. When a piece of metal is too long it can be shortened by upsetting, or when it is too thin at a certain place it can be thickened by the same method. This is done by having the metal hot only at the point or place where the upsetting is required. It is frequently necessary to cool the metal where the heat is not needed in order to confine the upsetting to the desired place.

Upsetting is not a very difficult operation as long as the metal is kept perfectly straight; otherwise the taskwill prove tedious and the metal may break from the constant bending back and forth. Bending will always take place, but breaking generally can be prevented by having the metal hot when it is straightened. The greatest difficulty in this respect will be experienced when operating on common wrought iron.

Upsetting by hammering is done by holding the metal perpendicularly on the anvil or something solid enough to withstand the blows which will be delivered upon it. Figure36shows this method.

Fig. 36.—Upsetting by Hammering.

If the end of a bar is being upset, and the upsetting is supposed to extend up through the bar for some distance, the heated end should be placed on the anvil as shown in the figure, because the anvil will slightly chill the end of the bar, and the upsetting will continue much fartherthan if the blows were delivered on the hot end. Striking the hot end with the hammer increases the diameter of the end excessively, because the contact of the hammer does not have a tendency to cool the metal.

Fig. 37.—“Backing up” Metal.

Another method of upsetting with the hammer, which is called “backing up” the metal, is shown inFig. 37. This method does not upset the metal so rapidly, because the force of the hammer blows jars the hand and arm which hold the bar.

Upsetting by ramming or jarring is thrusting the metal forcibly against some heavy object like the surface plate, the swage block, or the anvil. Figure38shows upsetting by this process. This method is very effective and is used mostly when the metal is long enough to be held with the hands, as shown.

Fig. 38.—Upsetting by Ramming.

56. Formingis a term generally applied to the making of a forging with special tools, dies, or forms. Thisprocess may include bending, punching, and other operations.

Swages are used for forming. A block of steel with a depression of a special design is known as a forming die; a number of other tools and appliances may be used for forming, but it is needless to mention them here.

57. Straighteningis one of the most frequent operations. When metal is being forged, the various blows have a tendency to make it crooked, and if the work is supposed to be straight when finished, it should be so.

Fig. 39.—A,Straightening with the Hammer;B,Straightening with the Swage.

There is as much skill required to straighten properly a piece of metal as there is to bend it. The most common method (A,Fig. 39) is to hold the metal lengthwise on the anvil with the bowed side or edge upwards, then to deliver the blows at the highest point of the bow. The blows will be most effective at the point where they are delivered, so they should be distributed in order to get the object perfectlystraight and to avoid making unsightly hammer marks.

If the metal to be straightened is round, or if it is flat with round edges, it is best to use a top swage of the proper size and deliver the blows on the swage as shown atB,Fig. 39. Then the surface of the round or the edges of the flat stock will not show any marks. The flatter or round-edged set hammer may be used in the same manner on flat or square material.

Fig. 40.—Straightening Wide Metal.

When wide pieces of flat metal are to be straightened edgewise, and such blows as are shown atA,Fig. 39, are not effective, then the blows should be delivered along the concave edge as shown inFig. 40, and distributed as indicated by the dotted circular lines. Blows delivered in this manner will stretch or lengthen the metal on the concave edge and straighten it.

58. Twistingis the operation of rotating metal to give it a spiral appearance. It may be done either hot or cold, as the dimensions of the material may require. It is done by holding the material in the vise, the hardy hole, or the swage block, and turning one end of it with a pair of tongs or a monkey wrench as many times as may be required. The twisting will be confined between the places where it is held with the vise, and where it is seized by the tongs or wrench.

If the material to be twisted is heavy enough to requireheating, a uniform heat is necessary or the twist will be irregular, and, as an artistic appearance is usually desired, this operation should be carried out with that result in view.

Fig. 41.—A,Metal Twisted while Hot;B,Metal Twisted while Cold.

A,Fig. 41, illustrates a piece of1⁄2-inch square stock that has been twisted while hot.Bshows a piece of1⁄2×1⁄8-inch material that has been twisted cold.

Another difficulty met with in twisting a piece of metal is that of its becoming crooked. It can be straightened by laying the twisted portion on a wooden block and striking it with a wooden mallet. This will prevent the corners from becoming marred. A good method of avoiding this trouble is to twist the metal inside of a piece of pipe whose inside diameter is equal to the diameter of the metal.

59. Welding, the most difficult operation in the art of forging, is the process of joining two or more pieces of metal into one solid mass.

All the previous operations allow some time for thought; in welding, the worker must determine instantly where each blow is to be delivered, as the welding heat of the metal vanishes rapidly; therefore, he is compelled to think and act very quickly.

A scientific analysis of a perfect weld shows that it consists of several processes, and that each one must be perfectly executed. If any of these operations are improperlydone, the result will be a partial failure; if they are essential ones, the weld may readily be considered as totally unfit.

60. The Material for Welding.—This must be considered, because there are different qualities in each metal to be operated upon, and some metals can be worked more easily than others.

A cross section of a bar of iron viewed through the microscope is seen to be made up of a great number of layers or fibers, called laminæ, resembling the grain or fiber in wood. These were cemented together in the process of rolling or welding in the mill where the iron was manufactured, and are continuous through its length. This makes the bar of uniform quality throughout.

In welding, these fibers are joined diagonally at the ends, consequently the strength of the weld depends entirely on how closely or perfectly this cohesion is made. Careful hammering at the proper heat brings the fibers in as close contact as possible, squeezes out the slag and scale, and therefore greatly assists in strengthening the weld.

Iron is an easy metal to weld. To prove this, place two pieces of iron in a clean, non-oxidizing fire, allowing them to attain a white or welding heat; then place them in contact and notice how readily they stick together, proving that iron is easily welded at the proper temperature. But in order to make the contact thorough, the pieces must be hammered. This shows that hammering is a secondary operation, and that iron cannot be joined by either heating or hammering alone.

By a similar experiment with soft steel, you will notice that the pieces do not adhere like iron. If borax is appliedwhile they are heating, then slight indications of adhesion will be noticeable. This shows that borax, sand, or something of a like nature must be used in welding steel. In this case hammering is not a secondary operation, but an essential one.

A higher carbon or tool steel may be experimented upon, with nearly the same result. The noticeable difference between the lower and higher qualities of steel proves that the greater the quantity of carbon, the harder will be the welding, and if the experiments were extended to still higher carbon steels, it would be discovered that they could not be joined except by the use of a specially prepared flux. There are indeed some high carbon steels that cannot be welded.

If a forging is to be made of a special quality of material, it is frequently advisable to avoid welds, because two pieces that are welded can hardly be considered so strong as a piece of the same material that has not been welded.

The weldings which are alluded to here are such as are used by practical blacksmiths in their general work without any special appliances or apparatus whatever. The majority of the exercises on welding in this book require the use of iron; for this reason this preliminary consideration of metals need not have any further special attention.

61. Heating.—When the word “fuel” is used here, either coal or coke may be meant. Coal is the original in either case, for coke is formed from it by the removal of gaseous substances. It is better that the coal first be converted into coke, and that only the coke should come in direct contact with the heating metals.

Fig. 42.—Sectional View of a Blacksmithing Fire.

Figure42shows a sectional view of a blacksmithing fire:dis the bed of hot coke;cis the dampened and unburned coal which surrounds the fire, continually forming more coke as it is needed and also holding the fire in a compact form;ashows the proper way of placing the metal in the fire,b, the improper way because the metal is too near the entrance of the blast. As heating is such an important operation, a thorough understanding of what causes imperfect heats, as well as how to prevent them, is necessary.

The best fire for perfect heating is a reducing one, that is, one in which the combustion of the fuel is rapid enough to use entirely the oxygen in the air which is supplied. An oxidizing fire is one that does not use all the oxygen in the blast for the combustion of the fuel. The surplus oxygen will produce, on the surface of the metal, oxide of iron, or a black scale, which is extremely injurious. This scale will prevent welding, so all possible precautions should be taken to avoid its forming.

A reducing fire can be maintained, and an oxidizing one avoided, by having plenty of fuel surrounding the metal,equally, and allowing the entrance of only sufficient air or blast to provide the necessary heating.

If a piece of metal is left in a fixed position while heating, the lower side will become the hottest. For that reason, all metals to be welded are placed with scarfs downward. If the required heat is to be a penetrating and thorough one, the metal is turned frequently to bring all surfaces in contact with the most intense point of heat.

Even though every possible precaution is taken in all other steps of the welding, the pieces cannot be joined perfectly if the heating is carelessly done.

62. Scarfing.—This is the operation of preparing or shaping metal for welding. There are five general kinds of welds, the distinct form of each depending either on the quality of the material or on the shape of the desired forging. They are called the lap weld, the cleft weld, the butt weld, the jump weld, and the V weld.

63. The lap weld(Fig. 43) is so called because the pieces lap over each other when placed in contact. It is most commonly used in general practice, and all welds formed in a similar manner belong to this class, regardless of the sectional form of the material or the shape of the completed weld.

Fig. 43.—Lap Weld Scarfs.

The pieces should always be upset where the scarfs are to be formed, to provide excess metal for welding. They should be formed with their end surfaces convex, and at an angle of about 45 degrees, which would not make the joining surfaces too long.

When the fire and all tools are ready, place both scarfs face down in the fire; when they are removed to the anvil,the piece held in the right hand should be turned face up and rest on the anvil, in order that the other may be placed in position on top of it.

The left-hand scarf should be placed carefully, with its point meeting the heel of the other. If placed too high and overlapping, it will increase the surface to be welded and perhaps decrease the dimensions of the material where the points are welded down upon the exterior. If placed too low, in all probability the surplus metal provided by upsetting will not be sufficient to form the weld to a uniform dimension. A little practice with the scarfs before heating is advisable to prevent this difficulty.

The hand hammer should be placed conveniently on the anvil, with the handle projecting sufficiently over the heel so that it can be grasped quickly with the right hand as soon as the two pieces are in position. If this precaution is not taken, the welding heat may disappear before any blows can be struck.

The first blows after the pieces are placed should be directed toward the center of the scarfs; when the center has been thoroughly united, the blows should be directed toward the points to complete the operation, if this can possibly be done in one heating.

It is impossible to give an invariable routine of blows; those given are sufficient for the beginning, the rest must be left to the observation and skill of the operator. Practice and judgment will determine where the blows should be delivered, and when they should cease.

As the welding heat vanishes very rapidly, it requires careful judgment to determine when the pieces cease to unite. All blows delivered after this will reduce the dimensions of the metal; if reheating is necessary, thereshould be no metal sacrificed by unnecessary hammering. Welds are generally weaker than the metal from which they are made; consequently if the stock is made smaller at the weld, its strength is greatly decreased.

The old adage “Haste makes waste” does not always apply. If you hasten the operation of welding while the pieces are sufficiently hot, you will not waste the metal. If through want of haste you are compelled to reheat, you will waste metal, for every time a piece is heated it loses a fractional part of its area, regardless of any hammering.

Welds made with scarfs of this kind are considered to be nearly as strong as the metal itself, because they allow of a more thorough lamination by hammering than other welds, consequently they are frequently used on various qualities of metal when strength is considered a chief requirement.

Fig. 44.—A,Cleft Weld Scarfs;B,Butt Weld Scarfs.

64. The cleft weld(A,Fig. 44) is so called because one piece of metal is split to receive the other. It is used for welding iron to iron or steel to iron (the inserted portion being the steel). Whatever the metal, the inserted portion is usually roughened with a hot cutter on the pointed surfaces and the cleft hammered down and securely fitted before the whole is heated. The pieces should not be placed in the fire separately, but together, as they have been fitted.

When a welding heat appears, if possible, light blows should be delivered on the end of the inserted portionwhile the two are in the fire; these blows will partly join the pieces and make them secure before removal. If this cannot be done, the first blows after removal from the fire should be on the end. When a final and thorough welding heat has been attained, they should be removed to the anvil and securely joined. If heavy pieces are being operated upon, they may be welded with the steam hammer.

65. The butt weld(B,Fig. 44) is so called because the pieces are butted together and almost thoroughly joined by ramming or backing-up blows before any blows are delivered on the exterior surface. The scarfs are easily formed. The outer edges of the pieces are backed up to form a rounded or convex end to insure their being joined at the center first. As the blows are delivered on the end, the metal will upset and the pieces will be joined from the center to the outer edges. After they have been quite thoroughly joined with these blows, they should be hammered on their exterior to weld them securely.

When scarfed in this manner, the pieces are frequently placed in the fire for heating with the ends in contact, then partly joined while in the fire and removed to the anvil or the steam hammer for final welding.

Fig. 45.—Jump Weld Scarfs.

66. The jump weldis shown inFig. 45. The scarfs require perfect forming, because the opportunityfor hammering is limited, as blows can be delivered only at certain places: on the end of the scarf 1 driving it into the concave groove 3; on a fuller which is held in the fillet 4; and on both the edges indicated at 3.

The groove at 3 should be formed with sufficient metal at points 0, to meet the projectionsX, and form a fillet. The convex scarf 1 should first come in contact at 3, so that welding will proceed from that place.

Welds made in this way are considered the weakest of those here described, on account of the limited assistance which can be provided by hammering. Still they are frequently used to avoid the laborious operations required to make such forgings out of solid metal.

Fig. 46.—V Weld Scarfs.

67. The V weld(Fig. 46) is a very important but difficult one. It is generally used on extremely heavy work, such as locomotive frames (Fig. 47), beam straps, rudder stems, and all cumbersome forgings.

The process is as follows: Pieces 5 and 6 are to be welded. They are held in a rigid position with heavy straps and bolts, as shown on the locomotive frame inFig. 47, sometimes while the V-shaped opening is being formed; however, they must always be held secure while the welding heat is being obtained. The V-shapedopening formed by the scarfs on 5 and 6 should penetrate about two thirds of their thickness and form an angle of about 50 degrees, with sufficient metal at9to provide for the waste which will occur while a welding heat is being procured.

The wedge 7 is formed with some surplus metal for filling the V-shaped opening. It is handled by a bar which is welded to it. The angle of the wedge should be not less than 5 degrees smaller than the angle of the opening. This will insure that the welding proceeds from the apex or point of the wedge outward.

Two fires are required; 5 and 6, securely strapped and bolted together, are placed in one with the V-shaped opening turned downward. Plenty of coke is placed around this opening, completely covered with moistened coal, and securely packed with a shovel; then two openings or vents are made through the coal with a poker, one on each side of the metal and leading to the scarfs. This is called a covered fire. The blast is now turned on and slowly increased until the proper heat is attained. The progress of heating can be observed through the openings thus made, and the fire replenished with coke when necessary.

These operations are supervised by the smith who has the work in charge, with two or more helpers or assistants, according to the size of the forging. The wedge 7 also is heated in a covered fire with only one opening on the workman’s side of the forge; the wedge is inserted in that opening, and is attended and handled by another smith, who watches its progress in heating.

When the supervising and attending smiths have signaled to each other that the heats are ready, 5 and 6are removed, turned over, and placed on the anvil or on the steam hammer die to receive the wedge which is placed in position by the attending smith. After the wedge has been thoroughly welded into place with either sledges or steam hammer, the handle and all surplus metal surrounding the openings are removed by the aid of hot cutters and sledges.

This procedure must now be repeated and another wedge welded into place on the opposite side indicated by the broken lines. With these two wedges 5 and 6 will be securely joined.

To insure a perfect weld, a good quality of material should be selected for the wedges. It should be thoroughly hammered to produce good texture, and if iron is operated upon, the fiber of the wedges should run parallel to the fiber of the piece to be welded. As this is not generally observed, welds of this character often break through the centers of the two wedges.

Fig. 47.—A Broken Locomotive Frame.

The broken locomotive frame shown inFig. 47would be repaired by the above method. The irregular line atAshows where the break has occurred. The straps and bolts atBindicate the method of holding the parts in alignment. Two tie rods atCprevent the parts from separating.

Questions for Review

What effect is produced by the upright blow? By the edge-to-edge blow? By the overhanging blow? By the beveling or angle blow? By the leverage blows? What are the backing-up blows used for? The shearing blows?What is meant by forging? How many different operations are used in forging? Name them. What is meant by drawing? What tools may be employed in drawing metal? If you desire to increase the length more than the width, how should you hold the metal on the anvil? Why? What precaution should be observed in revolving metal when it is being drawn into a round form? What is meant by bending? Can iron of any sectional shape be bent? Which is the easiest to bend? What shapes are difficult to bend? How are these difficulties overcome? What is meant by upsetting? Explain how it is done. What difficulty is often experienced in upsetting? What is the difference in effect between resting the heated end on the anvil, and striking on the heated end while upsetting?What is meant by forming? What other operations may be involved? What special tools or appliances are sometimes used for forming? State what has been said about straightening? Does it require much skill? Would it be as easy to straighten a wide flat piece of metal, as it would a round one? Why? Explain the operation of twisting. Why is it generally done? How can twisting be done and keep the work perfectly straight? Explain the essential parts of a weld. Is a weld as strong as the original unwelded bar? Can all iron and steel be welded? What kind of fire is best for heating? What is meant by an oxidizing fire? What effect does it have on the metal? How can an oxidizing fire be prevented? How should scarfs be placed in the fire? Why? If a penetrating and thorough heat is desired on a piece of metal, how can it be obtained? What is meant by scarfing? Are all scarfs formed alike? Name and describe the different kinds of scarfs and welds. Which one is considered the weakest? Why? On what kind of work is the V weld used?

What is meant by forging? How many different operations are used in forging? Name them. What is meant by drawing? What tools may be employed in drawing metal? If you desire to increase the length more than the width, how should you hold the metal on the anvil? Why? What precaution should be observed in revolving metal when it is being drawn into a round form? What is meant by bending? Can iron of any sectional shape be bent? Which is the easiest to bend? What shapes are difficult to bend? How are these difficulties overcome? What is meant by upsetting? Explain how it is done. What difficulty is often experienced in upsetting? What is the difference in effect between resting the heated end on the anvil, and striking on the heated end while upsetting?

What is meant by forming? What other operations may be involved? What special tools or appliances are sometimes used for forming? State what has been said about straightening? Does it require much skill? Would it be as easy to straighten a wide flat piece of metal, as it would a round one? Why? Explain the operation of twisting. Why is it generally done? How can twisting be done and keep the work perfectly straight? Explain the essential parts of a weld. Is a weld as strong as the original unwelded bar? Can all iron and steel be welded? What kind of fire is best for heating? What is meant by an oxidizing fire? What effect does it have on the metal? How can an oxidizing fire be prevented? How should scarfs be placed in the fire? Why? If a penetrating and thorough heat is desired on a piece of metal, how can it be obtained? What is meant by scarfing? Are all scarfs formed alike? Name and describe the different kinds of scarfs and welds. Which one is considered the weakest? Why? On what kind of work is the V weld used?

68. Staple.—Fig. 48. Drawing and bending. Material required: 5 inches of1⁄4-inch round iron.

Fig. 48.—Steps in Making a Staple.

Draw 1 inch of each end to a flat chisel-shaped point1⁄4inch wide; these drawn ends should be 13⁄4inches long, leaving 3 inches of round stock between them. Heat the center and bend it, with points edgewise, to a semicircle of3⁄4inch inside diameter. These ends should be of equal length, parallel and straight.

When drawing the ends, heat the metal to a white heat to prevent the fibers from splitting or separating. Heat only to a cherry red for bending, to prevent heavy scaling, which is one cause of rough-appearing work. Rough work may also be caused by improper use of the hammer in striking too hard or frequently at one place. (SeeFig. 48for dimensions and stages.)

69. Draw Spike.—Fig. 49. Bending and drawing. Material required: 7 inches of1⁄4-inch round iron.

Fig. 49.—Steps in Making a Draw Spike.

Bend 31⁄4inches of one end nearly to a right angle; have the inner corner almost sharp and square, the outer portion circular at the corner. Then form a perfectly circular eye of the 31⁄4-inch end, having the center of the eye in line with the central portion of the stem. When drawing the point, first draw it square, then octagonal, and then finish it to a round. (SeeFig. 49for dimensions and stages.)

70. S Hook.—Fig. 50. Drawing and bending. Material required: 5 inches of1⁄4-inch round iron.

Draw1⁄2inch of each end to a smooth, round point; this should make the length from point to point 61⁄4inches, and the central portion for 4 inches should be full-sized1⁄4-inch round. Using half of the entire length, bend the first hook to an inside diameter of7⁄8inch, then bend the remaining half in the opposite direction to the same diameter, bringing both points directly toward each other, as shown.When heating for bending, be careful to avoid burning the points. (SeeFig. 50for dimensions and stages.)

Fig. 50.—Steps in Making an S Hook.

71. Pipe Hook.—Fig. 51. Upsetting, forging, and bending. Material required: 9 inches of1⁄2-inch square. Norway iron or soft steel is best for this exercise.

(Caution.To avoid injuring the fiber of the metal and to upset it rapidly with the least amount of labor, always have the metal perfectly straight, and heat it only where the upsetting is required.)

Bring 4 inches of the central portion of the material to a white heat; if the heat extends beyond that distance, cool 21⁄2inches of each end, then the upsetting will be confined to the desired place. Cool the ends quickly and thoroughly, so that the upsetting blows may be delivered before the heat has vanished. The material should be held vertically with the lower end resting on the anvil, while heavy blows are delivered on the top end, thus upsetting the heated metal.

Fig. 51.—Steps in Making a Pipe Hook.

These operations should be repeated until the center is7⁄8inch thick one way, with all excess metal forged on one side, as ata, and the three others perfectly straight. Now form a shoulderb, with overhanging blows, about1⁄8of aninch from the center or thickest portion, but draw it no smaller than5⁄16of an inch at the bottom. Then draw the metal markedcto an approximate dimension of1⁄2×5⁄16inch. Form this shoulder perfectly square, by holding it over a square corner of the anvil and delivering backing-up blows on the heavy end, while the drawn part rests flat on the anvil; the metal should be hot at the shoulder and cold on the end where the blows are to be delivered. Then use the flatter on the drawn end to smooth and drawit to the finished dimensions of1⁄2×1⁄4inch, making it perfectly smooth and straight on all sides. Cut off this drawn end 6 inches from the shoulder, as shown atd.

Draw the heavy end to a sharp, square point, making it straight on the side opposite to the shoulder and tapering from a point about 21⁄4inches from the shoulder; this should also be made smooth with the flatter. Sketcheshows this so far completed.

Beginning1⁄2inch from the shoulder, bend the 6-inch end backward through its smallest dimension, to a semicircle of 3 inches inside diameter. An outline of the required semicircle should be inscribed on a plate, or models may be made to verify it. SketchFshows the completed hook.

72. Gate Hook.—Fig. 52. Drawing, bending, and twisting. Material required: 71⁄4inches of3⁄8-inch square mild steel.

Mark lightly with the hardy on two edges 11⁄2inches from one end, as shown ata. Form shoulders at these marks on three sides of the metal; do not make them too deep, as surplus metal will be required for bending here. Draw the metal at the shoulders just made, continuing to the end to5⁄16inch round and 21⁄2inches long. Sketchbshows the work completed to this point.

Mark the opposite end on the same edges and in a like manner 41⁄2inches from where the first shoulders have been formed; form shoulders at these marks and also draw down to5⁄16inch round, making the extreme end a smooth, round point, 21⁄2inches long from the shoulders, as atc. Both of these ends should be round and smoothly drawn with the hand hammer.

Fig. 52.—Steps in Making a Gate Hook.

Bend the straight, round end from the sideeto a rightangle, proceeding as follows: When placing the work on the anvil, have the sideeuppermost and the shoulder projecting over the edge of the anvil the thickness of the round, or5⁄16inch; then when the metal is bent, the inside corner will be formed at the proper place and the shoulder will readily form into a right angle on the outer side. Light upright and backing-up blows will aid in forming the right angle after it has been bent, provided the piece is held with the round end vertical and restingon the face of the anvil. If such blows are used while it is being held over the edge of the anvil, they will reduce the sectional dimensions and not materially aid in forming the angle. Sketchdshows this angle in solid lines. Now form the round portion of this angle into a circular eye, making the inside diameter1⁄2inch, with the center on a line with the center of the main stem. Sketchdshows this eye in broken lines.

Bend the pointed end in the same manner and in the same direction as the eye, having the distance between the eye and the angle 4 inches, as shown in sketchF. Now heat this end and cool the extreme corner of the angle to prevent its straightening, then form the hook to the dimensions given in the sketch.

Heat the central portion of the square metal to an even cherry red; hold the hook and 1 inch of the square portion securely in the vise; then grasp the other end with the tongs or wrench 2 inches from the vise, and revolve it once, thus forming a twist of the proper length. Before cooling this work, see that the eye and hook are parallel and the body of the hook is perfectly straight.

73. Door Hasp.—Fig. 53. Drawing, forging, punching, cutting, and bending. Material required: 7 inches of 1 ×3⁄16-inch mild steel.

Mark lightly with the hardy on the edges 1 inch and 31⁄4inches from one end, as ata. Form shoulders at these marks with edge-to-edge blows, as shown atb, so that the metal between them may be drawn to smaller dimensions. The shoulders should be formed not deeper than1⁄8inch at first, and the metal between them should be drawn to a corresponding dimension. Then forge the 1-inch end into a round eye, as atc, and punch a5⁄16-inch hole in its center,as shown atd. Now draw the metal between the eye and the shoulders to exact dimensions, 3 inches long,5⁄8inch wide, and3⁄16inch thick, as shown atd.

Fig. 53.—Steps in Making a Door Hasp.

Mark the other end in the same manner 21⁄2inches from the shoulders, and form new shoulders at these marks with edge-to-edge blows. Draw the metal to a length of 21⁄8inches, making it5⁄8×3⁄16inch at the shoulders and1⁄2×1⁄8inch at the end; the extreme end should be forged round. SketchEshows these operations completed.

Locate the center of the 21⁄2-inch length; from that point place a center-punch mark7⁄8inch each side of the center and punch a5⁄16-inch hole at each mark with a hand punch, by placing the outer edge of the punch at thecenter-punch mark. Deliver no blows on the edges of this metal after the holes are punched.

Using a sharp, hot cutter, remove the metal between the holes, by cutting it equally from both sides, thus forming the slot as indicated by the broken lines in sketchE. By placing it over the hardy, straighten the metal which forms the sides of this slot, and all other portions, so that all edges will be straight and parallel to each other. Smooth all flat surfaces with a flatter, using water to remove the scale of oxide. If the marking and punching of the holes have been carefully done, the inside length of the slot will now be 2 inches.

Bend the 21⁄8-inch end to a right angle at the shoulders, having the length from the inside of the angle to the outside of the eye about 7 inches. Heat this entire end and quickly cool the extreme corner of the angle to prevent its straightening there, then form the hook to the dimensions given in sketchF. The inner edges of the slot may be filed straight and parallel to the outside edges, but the semicircular ends which have been formed by the punch should not be disturbed.

74. Hexagonal Head Bolt.—Fig 54. Upsetting and forging to a hexagonal cross section. Material required: 7 inches of1⁄2-inch round iron.

Heat one end to a white heat, then cool off 41⁄2inches of the opposite end, thus confining the upsetting to the required area; upset the hot end until its diameter is3⁄4inch, and the length over all is about 51⁄2inches.

It is important that the 41⁄2inches be kept perfectly cold, to prevent upsetting there, also to prevent its sticking fast in the heading tool, or possibly using more metal than is required for forming the head.

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