RM (Rectangular Modulus) Cores: arose due to the demand for coil formers with integrated pins that allow for efficient winding and high PCB packing densities.


Clamps engaging in recesses in the core base hold the cores in place, meaning glue is not normally required in this process.


All the cores adhere to specifications laid down in IEC 431 and DIN 41980. The coil formers adhere to DIN 41981.

RM cores are designed for two main applications:

  • Highly stable, extremely low loss filter inductors and other resonance determining inductors (F58, P11).
  • Low distortion broadband transmission at low signal modulation (F39, F10, F9).

 RM cores can also be supplied without the centre hole. These have a higher AL value and cross-sectional area and are used for power transformer applications (F47, F44, F45, F5A).



RM4,RM5, RM6, RM7, RM8, RM10, RM12, RM14