Stelco RF Wire-Wound Chip Inductors Sumida Stelco RF Wire-Wound Chip Inductors offer extraordinary Q-factors combined with high SRF. Multi-case sizes and multi levels of inductance allow for optimal circuit design without compromise. Sumida Stelco RF Wire-Wound Chip Inductors are ideal for even the most-harsh environmental conditions, as well as antenna amplifiers, tuners, base stations, or SAT receivers.