If I understand correctly you want to roll a metal plate into a cylinder of outside diameter 2010 mm.

The perimeter or circumference of a circle is π × d where d id the diameter and hence the circumference of your cylinder is

π × d = π × 2010 = 6314.6 mm

Thus if you take a sheet of metal 6314.6 mm long and roll it into a cylinder the cylinder will have outside diameter of 2010 mm.

Harley

In February 2022 we received this message from Evan, a Professor of Welding

I noticed a problem with one of your answers about rolling 6mm thick plate into a cylinder. You didn't take into account the thickness of the material. When steel is rolled, it's outside stretches slightly and the inside compresses slightly. The diameter should be the mean diameter (outside diameter minus material thickness or insidediameter plus material thickness). This will account for the stretch and compression.

Hence the value d above should be 2010 - 6 = 2004 mm which gives a circumference of

π × d = π × 2004 = 6295.8 mm.

Thanks for this Evan.

Harley