1 Ngultrum magnetic

The magnetic 1979 Ngultrum was struck in copper-nickel clad steel as part of a broader shift toward cheaper, more durable coinage materials that several smaller Asian nations adopted in the late 1970s under pressure from rising nickel and copper commodity prices. Bhutan's Royal Advisory Council authorized the change without fanfare, and the two compositions — magnetic and non-magnetic — circulated concurrently, largely unnoticed by the general population.

The clad steel variety is catalogued separately under KM#49a precisely because the substrate difference is not visible to the naked eye, only detectable by magnet.