Semihard magnetic alloys of Fe-Co-W have been developed for application in remanent reed switches. These alloys are very ductile and can be processed into fine wires. The 78%Fe-12%Co- 10%W alloy shows the magnetic properties: B r = 19.2 kG, B r /B 200 = 0.95, and H c = 25 Oe. These magnetic properties are superior to those of the commercially used Remendur (49%Co-48%Fe-3%V) or Nibcolloy (85%Co-12%Fe-3%Nb), and the alloy itself consists of a much less expensive cobalt content than those alloys. This 78%Fe-12%Co-10%W alloy is flattenable into reeds, plateable with contact materials, and sealable in glass vials without losing its magnetic properties. Fe-Co-W alloys are adequate for use in remanent reed switches and present distinct advantages from the aspects of their inexpensiveness and superior characteristics.