On the application side, you will need to know the minimum and maximum diameter of the cylinders to be formed.

The harder materials and laser/plasma cutting techniques used today require hard outer roll surfaces on rolling equipment. A hardness rating from 50 to 55 Rockwell C scale will have a reasonable penetration depth and provide long-lasting protection against roll surface wear. A hardness rating exceeding 60 will have a shallow penetration and will likely result in cracking or crazing of the roll surface.

You’ll also need to know if you will be making cones or special shapes as this will determine the correct type and size of plate roll.

Unlike traditional three-roll cylinder machines, the lower rolls on three-roll, variable geometry machines move horizontally right to left, and the upper roll moves up and down. As on four-roll machines, material loads parallel to the floor, so the machine pit can be constructed to working level.

Side rolls positioned to the right and left of the bottom roll and on their own axes. The independent axis of each roll helps make a perfect bend. The back side roll (at the far side of the feeding point) also functions as a back-gauge to square the plate for proper alignment which eliminates the need for someone to assist the operator.

Single initial-pinch plate rolls are generally only suitable for light-capacity applications. They can be electromechanical or hydraulic and work by pinching the flat sheet between two vertically opposed rolls while the third bending roll moves upward to contact then bend the sheet. These tend to be older machines which in most applications require removal and reinsertion of the sheet to prebend both ends so although cost-effective they are more labour-intensive in a production setting than their modern counterparts.

Three-roll, double-pinch machines are available in light to very heavy capacities and do not require the operator to remove, flip, and then try to square the plate a second time after pre-bending, as is the case with three-roll, initial-pinch machines. Cylinders can be rolled to the required diameter immediately following pre-bending because the material can be kept in the machine (this is not possible in three-roll, initial-pinch machines.)

Side rolls positioned to the right and left of the top roll and are on the same axis. The axis of each roll helps make the bend. The back side roll also functions as a back-gauge to square the plate for proper alignment which eliminates the need for someone to assist the operator.

For cone rolling on a three-roll, double-pinch machine, the side rolls can be tilted to establish the cone angle.

Will you be doing any welding in the plate roller?

It’s never normally something that is planned at the outset before you realise it, your welder is on top of the plate roller trying to join up the two ends. It can be convenient, but if it’s not done properly or without proper protection on the machine then controls and electrical systems could be damaged. If this is even a possibility for your machine fabricating operation then you need to have an upgraded, shielded electronic system to protect the plate rollers’ electronics.