Above, the only two tools in my possession that were made by this company: a hermaphrodite caliper and a centre punch.
The Union Tool Company was founded in 1908, and specialized in machinist's tools. It was bought by Millers Falls in 1957, under whose management its products were badged as Union, Millers Falls or Sears. The company was wrapped up in 1975 and the factory sold to private investors who formed a new company, Sojo. It apparently lasted for another decade. For more on the company's history, visit Old Tool Heaven.