The Diamond Calk Horseshoe Company of Duluth, Minnesota

Duluth, Minnesota

Duluth is a port city in the U.S. state of Minnesota and is the county seat of Saint Louis County. The fourth largest city in Minnesota, Duluth had a total population of 86,265 in the 2010 census. Duluth is also the second largest city that is located on Lake Superior after Thunder Bay, Ontario,...

, USA was founded in 1908 by blacksmith Otto Swanstrom. Initially manufacturing horseshoes with a special type of calk

Caulkin

A caulkin from the Latin calx is a blunt projection on a horseshoe that is often forged, welded or brazed onto the shoe. The term may also refer to traction devices screwed into the bottom of a horseshoe, also commonly called shoe studs or screw-in calks...

 to improve the animals' foothold on slippery surfaces, the company successfully adapted to the development of motorised transport for the masses and produced a range of adjustable wrenches

Adjustable spanner

An adjustable spanner or adjustable wrench is a spanner with a "jaw" of adjustable width, allowing it to be used with different sizes of fastener head rather than just one faster, as with a conventional fixed spanner...

 and pliers

Pliers

Pliers are a hand tool used to hold objects firmly, for bending, or physical compression. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longer handles on the other...

from the 1920s. The family-owned company was sold to the Triangle Corporation in 1981.