. Official proceedings . be formed in a billet without theuse of the piercer point. The principle involved in forming the cavity: Indeed, sucha hole can be opened up in the center of any solid cylindricallyshaped plastic body by rolling it between, even, two flat sur-faces. Steel workers, particularly hamiiierman, are familiar withthe fact that, if a piece of steel in the form of a round be pressed. FIG. 2 (Mannesmann Pass.) or hammered into an oval form, several times in succession, arupture will occur in the center that will extend long-itudinally 10 through the middle of the bar. The reasrm
. Official proceedings . be formed in a billet without theuse of the piercer point. The principle involved in forming the cavity: Indeed, sucha hole can be opened up in the center of any solid cylindricallyshaped plastic body by rolling it between, even, two flat sur-faces. Steel workers, particularly hamiiierman, are familiar withthe fact that, if a piece of steel in the form of a round be pressed. FIG. 2 (Mannesmann Pass.) or hammered into an oval form, several times in succession, arupture will occur in the center that will extend long-itudinally 10 through the middle of the bar. The reasrm for the formationf)f this rupture is plainly due to the fact that when pressure isapplied to the round bar at diametrically opposite points suffi-cient to deform it, making- one diameter shorter and that at rightangles to it longer, the spreading of the metal, which takes placealong the long diameter and in opposite directions, sets up alateral tension that may cause its particles to be drawn awayfrom the center. See Figure i. Flow of the metal in piercing: This is the action that firstoccurs in the roll-piercing machine. As the billet, which is in aplastic state, enters the mill, the rolls grasp it at diametricallyopposite points on its circumference while it is yet about fourinches from their centers. As they draw the billet forward theycontinue to compress it at these opposite points, an
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Keywords: ., bookcentury1900, bookdecade1900, bookidofficialproc, bookyear1901
