Franklin Peale developed mechanical skills through work in his family's Philadelphia museum and in manufacturing. He helped create exhibits and machinery, worked with the engineer and locomotive builder Matthias Baldwin, and participated in the early activities of the Franklin Institute. This work combined craftsmanship, scientific instruction and industrial experimentation, preparing him for a technical role at the United States Mint.

Hired by the Mint in 1833, Peale traveled through European mints to study their equipment and processes. On returning in 1835 he recommended changes in refining, assaying and coin production. He helped introduce steam-powered coining presses and machinery for reducing engraved designs, as well as devices that made counting and handling coins faster. Appointed melter and refiner in 1836, he also assisted the new southern branch mints, visiting Charlotte and Dahlonega to investigate problems with buildings and equipment.

In 1839 Peale became chief coiner at Philadelphia, succeeding Adam Eckfeldt. His improvements increased the scale and regularity of production, but his position became embroiled in disputes over private medal work and the use of government facilities and employees. After investigations and prolonged controversy, President Franklin Pierce dismissed him in 1854. He spent later years seeking compensation for his services and inventions. His machinery and procedures continued in use at the Mint after his dismissal.