Forge Work :: CHAPTER III Practice Exercises

CHAPTER III Practice Exercises

68. Staple.—Fig. 48. Drawing and bending. Material required: 5 inches of ¹/₄-inch round iron.

Fig. 48.—Steps in Making a Staple.

Draw 1 inch of each end to a flat chisel-shaped point ¹/₄ inch wide; these drawn ends should be 1³/₄ inches long, leaving 3 inches of round stock between them. Heat the center and bend it, with points edgewise, to a semicircle of ³/₄ inch 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. (See Fig. 48 for dimensions and stages.)

69. Draw Spike.—Fig. 49. Bending and drawing. Material required: 7 inches of ¹/₄-inch round iron.

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

Bend 3¹/₄ inches 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. (See Fig. 49 for dimensions and stages.)

70. S Hook.—Fig. 50. Drawing and bending. Material required: 5 inches of ¹/₄-inch round iron.

Draw ¹/₂ inch of each end to a smooth, round point; this should make the length from point to point 6¹/₄ inches, and the central portion for 4 inches should be full-sized ¹/₄-inch round. Using half of the entire length, bend the first hook to an inside diameter of ⁷/₈ inch, 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. (See Fig. 50 for dimensions and stages.)

Fig. 50.—Steps in Making an S Hook.

71. Pipe Hook.—Fig. 51. Upsetting, forging, and bending. Material required: 9 inches of ¹/₂-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 2¹/₂ inches 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 is ⁷/₈ inch thick one way, with all excess metal forged on one side, as at a, and the three others perfectly straight. Now form a shoulder b, with overhanging blows, about ¹/₈ of an inch from the center or thickest portion, but draw it no smaller than ⁵/₁₆ of an inch at the bottom. Then draw the metal marked c to an approximate dimension of ¹/₂ × ⁵/₁₆ inch. 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 draw it to the finished dimensions of ¹/₂ × ¹/₄ inch, making it perfectly smooth and straight on all sides. Cut off this drawn end 6 inches from the shoulder, as shown at d.

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 2¹/₄ inches from the shoulder; this should also be made smooth with the flatter. Sketch e shows this so far completed.

Beginning ¹/₂ inch 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. Sketch F shows the completed hook.

72. Gate Hook.—Fig. 52. Drawing, bending, and twisting. Material required: 7¹/₄ inches of ³/₈-inch square mild steel.

Mark lightly with the hardy on two edges 1¹/₂ inches from one end, as shown at a. 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 to ⁵/₁₆ inch round and 2¹/₂ inches long. Sketch b shows the work completed to this point.

Mark the opposite end on the same edges and in a like manner 4¹/₂ inches from where the first shoulders have been formed; form shoulders at these marks and also draw down to ⁵/₁₆ inch round, making the extreme end a smooth, round point, 2¹/₂ inches long from the shoulders, as at c. 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 side e to a right angle, proceeding as follows: When placing the work on the anvil, have the side e uppermost and the shoulder projecting over the edge of the anvil the thickness of the round, or ⁵/₁₆ inch; 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 resting on 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. Sketch d shows this angle in solid lines. Now form the round portion of this angle into a circular eye, making the inside diameter ¹/₂ inch, with the center on a line with the center of the main stem. Sketch d shows 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 sketch F. 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 3¹/₄ inches from one end, as at a. Form shoulders at these marks with edge-to-edge blows, as shown at b, so that the metal between them may be drawn to smaller dimensions. The shoulders should be formed not deeper than ¹/₈ inch 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 at c, and punch a ⁵/₁₆-inch hole in its center, as shown at d. Now draw the metal between the eye and the shoulders to exact dimensions, 3 inches long, ⁵/₈ inch wide, and ³/₁₆ inch thick, as shown at d.

Fig. 53.—Steps in Making a Door Hasp.

Mark the other end in the same manner 2¹/₂ inches from the shoulders, and form new shoulders at these marks with edge-to-edge blows. Draw the metal to a length of 2¹/₈ inches, making it ⁵/₈ × ³/₁₆ inch at the shoulders and ¹/₂ × ¹/₈ inch at the end; the extreme end should be forged round. Sketch E shows these operations completed.

Locate the center of the 2¹/₂-inch length; from that point place a center-punch mark ⁷/₈ inch each side of the center and punch a ⁵/₁₆-inch hole at each mark with a hand punch, by placing the outer edge of the punch at the center-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 sketch E. 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 sketch F. 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 of ¹/₂-inch round iron.

Heat one end to a white heat, then cool off 4¹/₂ inches of the opposite end, thus confining the upsetting to the required area; upset the hot end until its diameter is ³/₄ inch, and the length over all is about 5¹/₂ inches.

It is important that the 4¹/₂ inches 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.

Fig. 54.—Hexagonal Head Bolt.

The upset metal should extend equally around the bolt. This will tend to prevent the head from forming unequally when the metal is being forged down on the heading tool. The head can be prevented from forming on one side by directing the blows toward the opposite side. Form the head by heating the upset end to a white heat, by inserting the opposite end in the heading tool, and by delivering upright blows on the heated end, unless others are required, thus forging down the upset metal to ¹/₂ inch thick. Remove it from the heading tool and forge the head into a hexagonal form. It will be necessary to insert the bolt in the heading tool several times to obtain the exact dimensions of the head, which should be ⁷/₈ inch through its short diameter and ¹/₂ inch thick. The chamfered finish on the top of the head is produced by using a button head set while the bolt is held in the heading tool.

75. Square-cornered Angle.—Fig. 55. Upsetting, chamfering, and forging a square corner. Material required: 10 inches of 1 × ¹/₂-inch iron.

Upset the center by cooling 3¹/₂ inches of each end to confine the operation to the required place. The center should be ⁷/₈ inch thick, and all upset metal should be forged to one side; the opposite side and both edges should be straight. Draw both ends tapering from where the upsetting ceases to ³/₄ × ¹/₄ inch at the ends; chamfer the edges of the drawn ends on the straight, flat side, beginning about 2 inches from the center and continuing to the ends. If the drawing and chamfering are properly done, each end will be 5¹/₂ inches from the center.

Fig. 55.—Upsetting for a Square Corner.

Heat and bend the stock at the upset center to a right angle, with the upset metal on the outer side to provide for the square corner. The bending should be done over the horn of the anvil to produce the quarter-round fillet on the inner side, and may be confined to the center by cooling both ends to where the upsetting begins.

As bends of this kind are somewhat difficult to make correctly, it would be a great advantage to provide a form which may be made to fit into the vise; then one end of the angle can be held securely with the form while the opposite end is bent over it. By any simple form it is impossible to make the outside corner perfectly sharp and square with one operation; it is therefore necessary to forge the outside corner sharp and square by delivering blows on both sides, somewhat in the manner shown in Fig. 56, but good judgment must be used in doing this.

Fig. 56.—Square-cornered Angle.

The chamfering may be marred or entirely removed in forging the corner; if so, rechamfer, and if the ends are of unequal lengths, the longer one should be cut off equal with the other. Then all surfaces should be made straight and smooth with the flatter and the scale removed by occasionally dipping the flatter in water.

76. Fagot Welding.—Welding and forging to dimensions. Material required: convenient pieces of scrap iron and a bar of ⁵/₈-inch round stock from 24 to 30 inches long.

Temporarily weld several separate pieces of scrap on to the bar until sufficient metal is provided for a thorough welding and forging of a solid piece of square iron 3¹/₂ inches long and ¹¹/₁₆ inch square. The welding should be done so as not to show where the pieces were joined. Forge it perfectly square and smooth with the flatter. Cut one end off square with a sharp hot cutter, then cut it to the required length.

77. Round Weld.—Fig. 57. Scarfing, welding, and swaging. Material required: two pieces of ⁷/₁₆-inch round iron, 4¹/₂ inches long.

Upset one end to ⁹/₁₆ inch, as shown at a. To form the scarf, deliver backing-up blows with the face of the hammer, as shown at b, and finish with blows delivered similarly with the ball. These backing-up blows will form the heel of the scarf. Draw out the point of the scarf with overhanging blows, as shown at c. The joining surface should be convex so that welding will proceed from the center. Scarf both pieces in the same manner, as at d.

Fig. 57.—Steps in Scarfing for a Round Weld.

Heat and weld according to instructions on welding and finish the work smoothly with swages; then cut to a length of 6 inches, having the weld in the center.

Properly formed scarfs will produce perfect welds provided they are heated to the welding temperature when they are joined, but those improperly formed generally produce imperfect welds, although the heat is right.

78. Flat Right-angled Weld.—Fig. 58. Material required: two pieces of iron ³/₄ × ³/₈, 4¹/₂ inches long.

Upset one end ¹/₈ inch larger than its diameters, as at a. By using backing-up blows as in the previous exercise, form a heel on one side, as shown at b, then resting the straight side on the anvil, draw out the point with the ball of the hammer, as at c. In drawing this point, the metal will spread and form a wide fan-shaped end, but by resting the right side d on the horn of the anvil and delivering blows on the left, the latter edge will be straightened, leaving all projecting metal on the right.

Fig. 58.—Steps in Scarfing for a Corner Weld.

Upset one end of the other piece to the same dimensions, allowing this upsetting to continue along the metal about 1 inch. Form a scarf on the left edge at e, with the ball of hammer, using blows similar to those shown at c and leaving the end square. Place them together to see if the points meet the heels; if not, make necessary alterations so they will.

Place the pieces in the fire, so that the side scarf will be removed with the left hand and the end scarf with the right. When placing for welding, the right-hand piece should be laid on the anvil and the left-hand one placed in its proper position on top of it. The inside corner should form a quarter-round fillet, the outside should be sharp and square, and the longer end cut off to make them both equal. Smooth all surfaces with a flatter. Sketch F shows the weld completed; the dotted lines indicate the location of the scarfs before welding.

79. T Weld.—Fig. 59. Scarfing and welding. Material required: two pieces of ³/₄ × ³/₈-inch iron, 8 and 4¹/₂ inches long.

Fig. 59.—Steps in Scarfing for a T Weld.

Upset one end of the shorter piece ¹/₈ inch larger than its diameters, and form a scarf similar to the first one for the right-angled weld, but here allow it to form fan-shaped and project equally over each edge, as shown at a.

Upset the center of the long piece to ¹/₈ inch or more larger than its diameters, with the upset portion fully 1 inch long, as at b. Form a scarf at this place with the ball of the hammer, allowing the metal to bend edgewise, as at c. Do not make this scarf quite so wide as the first one, as its edges should be entirely covered by scarf a without leaving any openings. See that they fit properly before heating for welding.

Especial care should be taken to have a good fire. The long piece should be placed in the fire so as to be removed with the left hand, and the short one with the right. Place the short piece on the anvil, with the long piece, held in the left hand, on top of and overlapping it sufficiently to prevent any openings. When welded, the long piece should be perfectly straight, with the short one at a right angle to it. Finish the weld with the flatter while it is at a dull red heat. Sketch D shows the T completed.

Fig. 60.—Chain Making.

80. Chain Making.—Fig. 60. Bending, scarfing, and welding links. Material required: 8 pieces of ³/₈-inch round iron, 6 inches long.

Heat and bend the center of each piece to a semicircle ³/₄ inch inside diameter; make the ends of equal length and parallel from the semicircle, as at a. Take one of these bent pieces and form a scarf on one end by holding it on the edge of the anvil at an angle of 45 degrees, as shown at b, and delivering overhanging blows, as indicated by the dotted circle, which represents the hammer. Turn the link over, placing the other end in the same position as the first, and scarf. Bend both scarfs toward each other equally until they overlap sufficiently to prevent any opening being formed, as at c; this is called closing the scarf.

Heat and weld the link by delivering the first few blows on its sides while it is resting on the face of the anvil, then by delivering lighter ones, while it is hung on the horn. While striking the light blows, do not hold the link in a fixed position, but move it to receive the blows around the circumference. The finished dimensions are 2 × ³/₄ inches inside; a slight variation in length does not make any difference, but their ends and widths should be uniform.

Proceed with another piece in like manner, but after scarfing it insert the finished link and continue adding new ones, until there are five links all together. The three extra pieces are for use in the next three exercises.

81. Welded Ring.—Fig. 61. Bending, scarfing, and welding a ring of round iron. Material required: one piece of ⁷/₁₆-inch round iron, 8 inches long.

Fig. 61.—Steps in Making a Ring.

Heat, and bend over the horn of the anvil about 1¹/₂ inches of each end to an inside radius of no less than 1 inch, as at A. Then heat the straight portion to a uniform temperature and bend it by holding the piece in a vertical position on the anvil, and delivering upright blows, as shown at B; this should produce a form similar to that shown at C. Continue the bending by holding the work as at D. By carefully observing the effect of these blows, you will be able to determine how the work ought to be held to produce the complete ring. These blows are used here to give the same effect as leverage blows. If the position of the metal is changed when and where it should be, almost a perfect ring may be produced without holding it on the horn of the anvil. It is not the best method to hold the work on the horn, because blows delivered in this way have a tendency to produce oval sections where they hit. In forming this ring the ends should be left open about 1 inch.

The directions for scarfing and welding are somewhat similar to those given for links, except that the angle of the scarf should be nearly a right angle. After the welding is completed, the ring should be made perfectly round by placing it over a mandrel or the horn of the anvil. When the ring is welded and complete, connect it to the chain with one of the extra links.

82. Chain Swivel.—Fig. 62. Bending, scarfing, welding, and riveting. Material: about 2 feet of ⁷/₁₆-inch round iron. Norway iron is the best, and this length is the most convenient for the first operations.

Fig. 62.—Chain Swivel.

Fig. 63.—Tool for Welding a Swivel.

For making this swivel, a special mandrel (Fig. 63) should be provided, made of ³/₄-inch round, mild or tool steel, with a short offset of ³/₄ inch; the gudgeon or pin which is shown at a should be 1¹/₄ inches long, ⁷/₁₆ inch in diameter at the shoulder, and tapering to ⁵/₁₆ inch at the end. Any convenient length of handle that will prevent burning the hand when welding, will do.

Bend about 2¹/₂ inches of the ⁷/₁₆-inch round stock to a right angle, as at a, Fig. 64; make the corner as square as possible, by upsetting it before bending; or after bending, by using upright and backing-up blows. Flatten the bent portion b parallel with the bar, by first delivering the blows with the ball of the hammer to increase the width as much as possible, then finish it to ³/₁₆ inch thick with the face of the hammer. The corner should be scarfed with the ball of the hammer and the rib worked out, as shown at c.

Fig. 64.—Steps in Making a Swivel.

Cut off the flat portion 2 inches from the bar, and form a thin scarf at the end of b. Notice that this should be formed on the same side with c. Beginning with the scarf at the end, the flat portion should be bent or rolled up so that the scarfs will overlap considerably, as indicated in the end view d. The special mandrel should now be inserted in the opening shown here, and all placed in a ³/₄-inch bottom swage, while the scarfs are hammered into close contact.

The long bar should now be cut off 4¹/₂ inches from the inside of the bend, and a fan-shaped scarf formed with the ball of the hammer, as at e. This should be drawn thin on the end and sides. The center of the 4¹/₂-inch length is next bent and the last scarf placed in position at f by again inserting the mandrel, placing it in the swage, and closing down the edges around the portions at f. It is then ready for welding. Figure 62 shows this in solid lines.

Fig. 65.—Making an Eye for a Swivel.

A good clean heat should be procured for welding; the mandrel should be quickly inserted, placed in the swage, and the welding done. This being completed, a small eye is to be made of ³/₈-inch round iron: first, by bending it in the form shown at a, Fig. 65; second, by inserting a punch in the opening and hammering the ends together, forming the eye, as shown at b; third, by welding these ends solidly together, as at c, and forging the whole to fit loosely in the swivel. The fitted end is now cut off square ³/₈ inch longer than the depth of the hole in the swivel, heated, and, while the eye is held in the vise, it is quickly riveted into place with a small straight or ball peen hammer. The eye is shown in place by the broken lines in Fig. 62. Connect this swivel to the chain with one of the extra links.

83. Chain Swivel.—Figs. 66 and 67. Fullering, forging, bending, welding, and riveting. Material: a piece of 1 × ¹/₂-inch iron, 4 or more inches long.

Using top and bottom fullers, form two sets of depressions not deeper than ¹/₄ inch, on each edge and opposite to each other, the first pair to be 1 inch from the end, the second pair 1 inch from the first, as at a.

Fig. 66.—Steps in Making a Swivel.

Draw the 1-inch end to ⁷/₁₆ inch round, leaving it slightly heavier where it was fullered to provide excess metal for further bending. The opposite end should now be cut off 1 inch from the fullered place and drawn to the same dimensions as the first end. Forge the central portion into a circular form and punch a ³/₈-inch hole in its center. Cut off all surplus material, making the ends 3¹/₂ inches long from the center of the hole, as at b.

Fig. 67.—The Completed Swivel.

Bend each end to a right angle close up to the eye and make the arms parallel and one inch apart, as at c. Drift the hole by driving the punch through between the parallel ends, thereby forming a slightly tapered hole. Scarf and weld the ends as you would a link. Make a small eye of ³/₈-inch round stock, proceeding in the manner explained in the previous exercise, also following the same instructions as to fitting, cutting, and riveting. Connect the link end of this swivel to the chain with one of the extra links. (See Fig. 67.)

Fig. 68.—Steps in Making a Chain Grabhook.

84. Chain Grabhook.—Fig. 68. Forging, punching, and bending. Material: one piece of ³/₄ × ³/₈-inch iron, 4¹/₂ inches long.

Form a depression as at a, ¹/₄ inch deep and ³/₄ inch from one end with overhanging blows. (The opposite edge should be kept perfectly straight during this and the following operations.) Forge the ³/₄-inch end into a circular-shaped eye ³/₈ inch thick, and punch a ¹/₄-inch hole, in the center, as at b. This hole should be drifted or expanded with a punch driven through from both sides alternately until the diameter becomes ¹/₂ inch.

By hanging this eye over the horn of the anvil so that the inner corners of the eye rest on the horn, by delivering blows opposite to those corners, and by changing its location so that blows will be delivered on all outside corners, the sectional form will be changed from square to octagon; by similar operations the form may be changed from octagon to round. During this change, light blows should be used in order to make the eye smooth. This stage is shown at c with a sectional view of the eye.

Fig. 69.—The Completed Chain Grabhook.

Proceeding from the eye toward the opposite end, forge both edges round to correspond with the eye, leaving the metal ³/₄ inch wide, 3 inches from the eye, as shown at d.

Draw the remaining section tapering from this extreme width to ¹/₄ inch, and forge the edges round as before. The hook should be ³/₁₆ inch round at the end and 3 inches long from the widest point, as shown at E. Heat the middle portion; cool the point and the eye, and bend the hook edgewise over the horn of the anvil toward the straight side, until the point is opposite the depression first formed. The inside semicircle formed by bending should be ¹/₂ inch in diameter, the other inside lines straight and parallel. The extreme point should be slightly curved away from the eye, and all flat surfaces hammered smooth with light blows while the hook is at a dull red heat. Figure 69 shows the hook completed. Using the remaining extra link, connect the hook to the swivel.

Questions for Review

What forging operations are employed in making the staple and the draw spike? What hammer blows are used on them? What caution should be observed in heating the S hook for bending? What operations are employed in making the pipe hook? Which is the most difficult? Where was the most difficult forging encountered? How was the point drawn? What operations are employed in making the gate hook? Explain how the angle should be bent, and how the blows should be delivered to make it square. Why should the extreme corner of the angle be cooled off before bending the hook? What operations are employed in making the hasp? Which one is used first? Into what form is the metal to be forged in making the bolt? What is meant by chamfering? What kind of hammer blows should be used in chamfering? Why should the metal be upset for the round weld? What special hammer blows are to be used in forming the scarfs? Explain how the scarfs are formed for the right-angled weld. How should scarfs be placed in the fire? How should they be placed on the anvil? Explain how the scarfs are formed for the T weld. Describe the scarfing of a link. Describe the welding of a link. What is the effect of bending the ring over the horn of the anvil? What operations are used in making the chain swivel?

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