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Rolling marks are usually divided into periodic rolling mark and non-periodic rolling mark. Periodic rolling marks distribute regularly on the H-Shaped Steel. It means the former and later marks appear at the same position and same depth of rolling piece. At the same time, these two marks’ interval is equal to their circumference. Periodic rolling marks are the bulges or craters that are made from little pits or attached oxydic tin on the grooves. Non-periodic rolling marks are usually distributes along the rolling direction. They are the ditches or pits that are made from serious guide device abrasion or rolling scratching steel products after the machine collision.
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