Pythagoras Mechanical Workshop Museum, Industrial heritage museum in Norrtälje, Sweden.

The Pythagoras Mechanical Workshop Museum is an industrial museum in Norrtälje, Sweden, displaying original machinery, production lines, and office spaces from a former engine factory. The collection spans a large site, allowing visitors to experience the complete working environment from that era.

The factory was founded in 1898 and initially produced mechanical calculators, later shifting to hot bulb engines. These engines were sold across Europe until production ended in 1979.

The company name comes from Pythagoras, chosen by the young inventors who founded it in 1898 and were drawn to occultism and number mysticism. The factory made hot bulb engines under the trademarks Fram and Drott, the latter for export, and these engines drove farm machinery and fishing boats. With around 80 employees it was once Norrtälje's largest industrial company.

The museum occupies the former engine factory buildings in Norrtälje, with production halls and offices shown as they were left when the workshop closed in 1979. The site is owned by the Engine Factory Pythagoras Foundation and run with the support group Pythagoras Vänner. The factory was declared a listed building in 1992, so the halls are preserved rather than rebuilt for display.

The name comes from Pythagoras, chosen by the young inventors who founded the company in 1898 and were drawn to occultism and number mysticism. Their original plan was to build mechanical calculators, which failed; the works then made locks and brass candlesticks before engines took over.