Profile measurement of bars behind a three-roll reducing/sizing block at von Moos Stahl AG.

von Moos Stahl AG produces very small lot sizes and therefore has to change sizes frequently. During start-up this requires dense control of diameter and profile along the billet to roll within the given tolerances as quickly as possible after size or grade changes.

Three-roll blocks can produce pseudo-rounds. When measured with a vernier gauge, these profiles show identical or very similar diameters at different angles even if their roundness is far out of tolerance. The result: product may be shipped as "in specs" although it does not meet size and ovality tolerances.

LAP have developed a patented measurement and evaluation method
(patents DE 100 23172 and US 6.549.293 B2) which precisely determines the sizes and roundness regardless of asymmetric or three-lobed shapes, thus allowing optimal control of rolling trains with 2- or 3-roll stands.