J H Humphreys and Sons was an electrical engineering firm established in Oldham, around 1891. The business moved to Milne Street in around 1930, remaining at the site until the business ceased to trade in 2007. The company number was 00548587. In 1918, Humphreys was promoting its magnetic chucks as the most powerful in the world. According to a source at the company, the founders of the firm came up with idea of using mains electricity to secure parts for grinding rather than using clamps. In the 2000s company literature described them as 'engineers and makers of magnetic chucks, demagnetisers, lifting magnets, wearing parts, shear blades and granulator blades'. J H Humphreys was forced to close due to the compulsory purchase of their land in 2007.