Overview leveling methods

An example for the typical time required to get flat flame-cut parts (in minutes)

Hammer and flame

A conventional flattening technique. The part is heated and then hammered into a flat condition. This technique is very time consuming and requires highly skilled workers.

Rolling machines

Fabricators also use rolling machines to remove rough flatness defects. Tight flatness requirements cannot be achieved with this procedure as internal stresses remain in sheet metal parts.  Handling is very challenging for large and heavy flame-cut parts. Time requirements can easily exceed 25 minutes per part.   

Straightening presses

The same is true for straightening presses commonly used for laser and flame-cut parts.  Time requirements of 20 minutes per part are not unusual.

Roller leveling

Roller levelers straighten laser and flame cut parts quickly and easily. Mechanical straighteners are used for parts with low flatness requirements as mechanical straighteners usually need 5 to 6 passes to render good leveling results.

Servo-hydraulic precision levelers

Servo-hydraulic precision levelers meet high expectations and achieve the tightest tolerances.  An example is the ARKU FlatMasterĀ®. The leveling rollers are spaced with minimal roller pitch and have excellent support. The leveling gap control feature maintains a constant leveling gap even with varying widths and cut-outs. In combination with small roller diameters these features provide dead-flat and stress-free parts in just one pass.   

Roller leveling

Roller leveling is essentially a bending process. The  out of flat part, sheet or plate is deformed by a series of alternating bends. These alternating bends are created by passing the part, sheet, or plate between upper and lower sets of leveling rollers. The leveling rollers are offset by half of the roller pitch in the direction of the travel. As a result, the sheet metal takes a wave-like path through the precision leveler. This wave should be greatest at the entry into the machine and smallest at its exit (comparable to a decaying sinusoidal curve). The elastic-plastic alternating bends and the constant decline of bending intensity thereby produce flat and nearly stress-free parts, sheets and plates.