Usine du May, Industrial heritage site in Thiers, France.

The Usine du May is a former cutlery factory in the Usines valley at Thiers, built in 1890 in the bed of the Durolle. Its facade has three levels: a rough grey stone base with four large arched openings, and two rendered upper storeys with tall arched windows framed in red brick. Painted lettering reads "MANUFACTURE DU MAY".

A grinding wheel stood on this spot by 1476, at the foot of the rock where Saint Genes was said to be beheaded. The small, flood-prone buildings were replaced in 1890 by a larger, brighter factory, linked to Avenue Joseph-Claussat by a footbridge. The cutlery firm Grange Jeune J. Lepage went bankrupt in 1900, and the building was split into rented assembly workshops. Electrified from 1903, it closed in the 1960s and was bought by the town in 1987.

The name "May" has no link to the site's history; it echoes the "Maison de l'Aventure Industrielle", the industrial-heritage centre housed here from 2009 to 2015. Since 2015 the building has served only for long cultural exhibitions run by the municipality of Thiers. Painted lettering on the facade still reads "Manufacture des soiers" and "Musée de la fabrique du May Le Coute."

The factory stands in the minor bed of the Durolle, between the Mondière forges upstream and the Creux de l'enfer factory downstream. A footbridge built between Avenue Joseph-Claussat and an annex workshop let workers and goods enter; the annex was demolished in the 2009 rehabilitation. The building covers just under 1,000 m².

A metal footbridge spans the river and provides an unusual way to reach the building. This arrangement was needed because the factory was built on a tight plot of land beside the Durolle River.