These are also named band excentric-rods, and are indicated by Figs. 45 and 115. The forked or hoop portion is of one piece with the remainder of the rod; although it is first forged distinct from the straight part, the two being afterwards welded together.

The hoop portion is formed by spreading out the end of a thick piece which is of sufficient length to be conveniently handled by means of tongs, or by a bar named a porter, which is welded to the work at the commencement of the forging. A round hole is made at the inner extremity of the intended gap, or concave portion of the hoop, and a slit is cut from the hole to the extremity of the work. After being thus divided, the two ends are reduced to a proper width and thickness, and increased to a suitable length, care being exercised to leave a thick piece at each end to be formed into bosses for the connecting-bolts.

After the semicircular portion is formed, a stem is made of the thick part of the work, which is produced to a convenient length for welding to the straight part of the excentric-rod. This straight part is then made of proper length, width, and thickness, and welded to the hoop-piece for completing the rod.

Large hoop excentric-rods for marine engines are made of several pieces, which are then welded together. One piece constitutes the boss part which is bolted to the link ; another piece is made into the intermediate parts of the rod ; the next piece is formed into the fork junction, being that which connects the intermediate piece with the fork-ends; and these two fork-ends are the portions required for completing the rod.

After the whole number are welded together, such large rods need careful adjusting to place the band portion at right angles to the straight part of the rod. To effect this adjustment, a straight line is marked upon a large surface-table, the length of the line being a few inches greater than the total length of the rod. At one extremity of the line another is made at right angles to the first, and across it, the length of the second line being equal to the total breadth across the gap and the bosses included. From the centre of this line two concentric circles are described, the distance between their two circumferences being an eighth of an inch greater than the distance between the two curves of the hoop-forks. Next mark the shape of the intermediate part of the rod, by drawing a line on each side of the first one made, and making the distance between the two outer lines an eighth of an inch greater than the width across the rod.

By placing the rod between these lines on a surface-table, any irregularity in the band or straight part of the work will be easily observed, and corrected accordingly.