How to Develop the Blank Flat Length for a Cylinder

To develop the blank flat length for a cylinder rolled from sheet or plate is quite simple:

Essentially, you should calculate the centerline arc:

(Outside Diameter – Thickness) x 3.1416 = Length of Plate Required

(Inside Diameter + Thickness) x 3.1416 = Length of Plate Required

Note:  Additional plate may be required depending on the material thickness and the machinery used.