Centreless lathe bar peeling inserts for steel (stainless steel, bearing steel, alloy steel, spring steel, etc.), copper, titanium, magnesium, aluminium and other round bars, tubes, coils and wires, turning processing, can quickly remove the bar surface cracks, oxidation or decarburisation layer and other defects, processing of high-precision high-quality bright bars, tubes, wires, the efficiency of more than the conventional process a few times to a dozen times.