Knowledge Matrix on Instagram: "called ring rolling. A solid steel block is first heated until it is red hot. A hole is pierced at the center to form a donut shape. This hot piece is placed on a rolling machine where rollers press and stretch it in a circular motion. The hole expands and the outer diameter grows until the ring reaches the required size. After rolling the ring goes through heat treatment for strength then machining and finishing for accurate shape and smooth surface. This process

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