Much of the expansion of Hayle came about through the development of Harvey’s Foundry and Engineering works during the late 18th and early 19th Century.

In 1779 John Harvey, a blacksmith from nearby Carnhell Green, established a small foundry and engineering works in the area, now known as Foundry, to supply the local mining industry. The business flourished and by 1800 employed more than 50 people.
Harvey & Company went from strength to strength through both professional and family partnerships with a series of great engineers and entrepreneurs.

Harvey & Co may be best remembered for producing beam engines, which not only served locally but were exported worldwide. The company also produced a range of products ranging from hand tools to oceangoing ships, including the SS Cornubia and the world's first steam-powered rock boring machine.

Harvey's of Hayle reached their peak in the early/mid-19th century but, along with the other foundries and engineering works in Hayle, began a long and slow decline.
Harvey's acquired the rival Cornish Copper Company in 1875 but the downturn continued.

The engineering works and Foundry were closed in 1903, although the company continued to trade as general and builders merchant, eventually merging with UBM to become UBM-Harvey in 1969.

In recent times UBM has become Jewsons which continues to trade from part of the original company’s site at Carnsew. Other parts of the former Harvey works have been conserved though the erecting shop was demolished in the 1980s and housing built on the site