John "Iron-Mad" Wilkinson (1728 – 14 July 1808) was an English industrialist who pioneered the manufacture of cast iron and the use of cast-iron goods during the Industrial Revolution.

He also developed a blowing device for blast furnaces that allowed higher temperatures, increasing their efficiency, and helped sponsor the first iron bridge in Coalbrookdale.

John and his half-brother William, who was 17 years younger, were raised in a non-conformist Presbyterian family and he was educated at a dissenting academy at Kendal, Westmorland (also now part of Cumbria), run by Dr Caleb Rotherham.

[4] When his father moved to Bersham furnace near Wrexham, north Wales, in 1753 John remained at Kirkby Lonsdale in Westmorland where he married Ann Maudesley on 12 June 1755.

He had houses either side of 'The Lawns' which served for administration, one being named 'The Mint' used for distribution of the thousands of tokens, each valued equivalent to a halfpenny.

Bradley became his largest and most successful enterprise, and was the site of extensive experiments in getting raw coal to substitute for coke in the production of cast iron.

[8] James Watt had tried unsuccessfully for several years to obtain accurately bored cylinders for his steam engines, and was forced to use hammered iron, which was out of round and caused leakage past the piston.

In 1774 John Wilkinson invented a boring machine in which the shaft that held the cutting tool extended through the cylinder and was supported on both ends, unlike the cantilevered borers then in use.

John Wilkinson took a key interest in obtaining orders for these more efficient steam engines and other uses for cast iron from the owners of Cornish copper mines.

The historian Joseph Needham likened Wilkinson's design to the one described in 1313 by the Chinese Imperial Government metallurgist Wang Zhen in his Treatise on Agriculture.

[11] In 1775 John Wilkinson was the prime mover initiating the building of the Iron Bridge connecting the then-important industrial town of Broseley with the other side of the River Severn.

A committee of subscribers was formed, mostly including Broseley businessmen, to agree to the use of iron rather than wood or stone and obtain price quotations and an authorising act of Parliament.

When construction started, Wilkinson sold his shares to Abraham Darby III in 1777, leaving the latter to steer the project to its successful conclusion in 1779 and be opened in 1781.

In 1761, the Royal Navy clad the hull of the frigate HMS Alarm with copper sheet to reduce the growth of marine biofouling and prevent attack by the Teredo shipworm.

After the success of this work the Navy decreed that all ships should be clad and this created a large demand for copper that Wilkinson noted during his visits to shipyards.

To help his business interests and to service his trade tokens, Wilkinson bought into partnerships with banks in Birmingham, Bilston, Bradley, Brymbo and Shrewsbury.

Wilkinson bought lead mines at Minera in Wrexham, five miles from Bersham, Llyn Pandy at Soughton (now Sychdyn) and Mold, also in Flintshire He installed steam pumping engines to make them viable again.

When he was in his seventies, his mistress Mary Ann Lewis, a maid at his estate in Brymbo Hall, gave birth to his only children, a boy and two girls.

He was originally buried at his Castlehead estate at Grange-over-Sands, raised above the adjoining moss lands which he drained and improved from 1778 onwards.