After this first phase of rapid expansion he decided to rationalize his production units and decided to make the Fesches-le-Châtel factory, his flagship site. When he passed away in 1812, the company was handed down to his three sons who, in turn, helped the business grow and build new factories. In 1849, Japy Frères manufactured the first stamped French saucepan in the Fesches-le-Châtel workshops.

Japy became France's second biggest industrial company during the era of the Second Empire.

The 1880's were the golden age of this fast-growing company, which had a number of further successes with typewriters, coffee grinders, garden furniture, light fittings, and many more.