Rolling and pre-bending
Check both capacities at the required plate width, material grade and finished diameter. Pre-bending capacity may be lower than the main rolling capacity.
Carter plate rolling guide
From flat plate
to a controlled curve.
Compare pyramid, initial-pinch 3-roll, double-pinch 3-roll and 4-roll arrangements. Calculate a starting blank length and check a rolled radius.
Four ways to roll plate.
Choose a configuration to see which rolls move and how their movement bends the plate. Use the slider below each animation to inspect the movement. These simplified motion studies explain the principle; actual controls, guarding and working sequences depend on the machine.
Initial-pinch 3-roll
A straightforward choice for general cylinder work. The plate is gripped by two rolls while the side roll forms the curve. Pre-bending both ends normally needs the plate to be turned end for end.
The lower pinch roll rises to grip the plate against the top roll; the offset side roll then rises to create the curve. The animation shows one pass. Reposition the plate end for end to prepare the opposite end.
Double-pinch 3-roll
Two independently adjustable side rolls allow both plate ends to be pre-bent in one insertion. This reduces handling compared with an initial-pinch arrangement.
Watch the two side rolls rise independently beneath the top roll. Changing their positions changes the plate curvature; there is no separate bottom pinch roll.
4-roll
A dedicated lower pinch roll holds the plate while two side rolls form the curve and pre-bend both ends. Well suited to repeat work and automated rolling.
The lower pinch roll rises to grip and stays in contact during forming. The two side rolls then move independently to create the bend. Roll guide paths vary by model.
Pyramid 3-roll
In this conventional pyramid arrangement, two lower rolls support and feed the plate while the top roll moves vertically. Lowering the top roll progressively increases the bend.
The animation shows a symmetrical three-roll arrangement with fixed lower-roll positions. Unlike a pinch-roll arrangement, it has no dedicated upper-and-lower gripping pair.
Allow for straight end sections: end preparation or trimming depends on the job and the machine. Confirm pre-bending requirements when choosing your rolls.
Geometry, before machine settings
Cylinder & arc blank length.
This estimates a uniform circular arc along the neutral axis. Seam gap, trimming and weld shrinkage are excluded unless you enter an adjustment. It does not calculate machine capacity, roll positions or springback.
Full-cylinder length chart.
All dimensions in mm. Inside diameter, k = 0.5, 360° cylinder and no fabrication allowances. Use the calculator for other sizes.
| Inside diameter | 3 mm plate | 6 mm plate | 10 mm plate |
|---|---|---|---|
| 250 | 794.8 | 804.2 | 816.8 |
| 500 | 1,580.2 | 1,589.6 | 1,602.2 |
| 1000 | 3,151.0 | 3,160.4 | 3,173.0 |
| 1500 | 4,721.8 | 4,731.2 | 4,743.8 |
| 2000 | 6,292.6 | 6,302.0 | 6,314.6 |
Check a radius from chord and rise.
Small rise-measurement errors can produce large radius errors on shallow curves. The result describes the measured surface, not the neutral axis.
Specify the job before choosing the rolls.
Material and springback
Tensile strength, yield strength and material condition are distinct. Stronger plate and elastic recovery affect the required machine and setup. A universal percentage cannot predict every job.
Your quotation
Send plate width, thickness, material grade, target inside or outside diameter, required pre-bend and production quantity. Include cone or special-shape requirements.