OVERLAP CORE & STEP-LAP CORE

Transformer laminations are manufactured in a wide range of sizes suitable for single-phase and three-phase transformers. Depending on design needs, cores may be assembled using overlap joints or step-lap (cross or longitudinal) joints. Laminations are cut, punched, and V-notched through CNC cut-to-length lines to achieve exact fit and consistency. Sheet processing is available for widths up to 470 mm and lengths up to 3000 mm.

Using advanced integrated software, we convert conventional core layouts into step-lap configurations and encourages manufacturers to adopt this improved design. The step-lap arrangement provides a smoother magnetic flux path at the joints, which helps reduce no-load losses in the transformer core by approximately 5–8%. Technical specialists are available to support customers during core assembly whenever required.

In addition, NPPL provides lamination assembly services tailored to customer specifications for both power and distribution transformers.