vintage sterling silver lapel pins/tie tacks Young Spring and Wire Corp Detroit

Lot of two vintage sliver industrial worker's reward lapel pin or tie tacks from the "L. A. Young Spring and Wire Corporation" in Detroit, Michigan. They are for 5 and 10 years and are marked "Sign of Superiority". Both pins are stamped sterling on the backs. We're not sure of the exact vintage of these pins, but are guessing 1930s through 1950s.

The five year pin is about 5/8" across and the 10 year pin is 3/4" high. They are tarnished.