Leveling Process

Four Steps to Perfection

The Leveltek stretch leveling process consists of:

  • Uncoiling
  • Stretching
  • Leveling
  • Re-coiling

Leveltek eliminates shape defects such as edge waves, center buckles, quarter buckles, crossbow or oil can, and mandrel breaks. The only measurable effect on the coil is a slight reduction in material width, and a slight increase in length. The changes to physical properties are minimal, and the process is guaranteed not to mark or scratch the surface being stretched.

Leveltek’s stretch leveler has the ability to stretch with the force of 1.25 million pounds, which allows flattening of metals beyond ¼-inch thick, or with yields in excess of 100,000 psi. Even with materials that can be flattened using other methods, our process provides a higher standard of flatness for critical or special surfaces that are:

  • Bright Annealed
  • Polished
  • Painted
  • Patterned
  • Plated/Coated

Leveltek can process coils in a wide range of thicknesses and weights.


Technology Comparison

Note: If significant width reduction has not occurred, as in the Roller Leveler example, permanent correction of length disparities has not occurred.


Metals & Defects

Add Value to Your Customers’ Businesses! The Leveltek process of stretch leveling corrects the flatness of specialty metal coils that are not commercially acceptable because of edge waves, center buckle, or other imperfections. Leveltek deals with:

Leveltek can also take material that is commercially acceptable, and improve it to satisfy the most difficult requirements.

Edge Waves

The flat portion of the strip is shown as length L, and the excess length present in the wavy edge is shown as Δ L1.

The same increment of wavy edge strip is clamped between two sets of grippers; one set fixed and the other moveable.

Center Buckle

The excess length ΔL1, shown here as a center buckle, can occur anywhere within the strip.


The stretching force F overcomes the yield strength of the metal to extend the moveable grippers away from the fixed grippers to permanently elongate the entire strip to L+ΔL2. The total length increase, ΔL2, must always exceed the original excess length ΔL1.