These simple blocks come in various sizes for marking or etching on different diameters. The block creates pressure on all sides and produces sharp marks. It is not advisable to mark over a range of more than approximately 150 degrees of the 360-degree circumference. To provide adequate electrolyte, contour blocks are usually set in well assemblies or they are available as marking cartridges. They are, of course, highly adaptable to our automatic metal marking machines.