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Inventions in Transport from Bradford


Hepolite was devoted to the manufacture of internal combustion engine components. The range of pistons, piston rings, piston pins and cylinder liners produced was the most comprehensive in the world. The company was founded in 1907 and moved to their main manufacturing plant of St Johnís Works, Bradford (see map view link below) in 1916.


It was company policy to be in a position to provide Hepolite products to suit any vehicle on the roads of the world as well as cater for industrial applications. The number of designs required to maintain this policy was huge and the company had a huge design drawing office to create blueprints for the production of an enormous range of products. The designers needed to stay in constant touch with the technical developments in the automotive world.


The company started to produce ring pots and piston castings for use in its own machine shops. A special section of the foundry was created in 1932 to produce piston rings for individual castings. The piston shops at St Johnís Works were making cast iron pistons. The manufacturing was on a large scale producing pistons to suit all different types of internal combustion engines, compressors, pumps and hydraulic units. The company prided itself on the fact that they could produce quantities ranging from a single piston to thousands of one design. This obviously required great flexibility in the layout and operation of the department. At one time the ring shop at St Johnís Works covered an area of 90,000 square feet and housed over 500 production machines. Each week these machines turned out over one million piston rings.


Hepolite also produced cylinder liners, the first stage of which was the production of a cast iron centrifugal casting. Hepworth and Grandage, the parent company, were pioneers in the production of cylinder liners. They claimed that Ďours is without doubt the largest unit of its kind in the world and our claim that we produce the widest available ranges of pistons, piston rings, piston pins and cylinder liners is beyond challenge.í

Map view of St John's Works, Bradford, site of Hepolite's first main factory»

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Comment on this page

  • Posted by My Learning on 20/10/2014

    Thank you Pauline and Mark for sharing your connections with Hepworth and Grandage!

  • Posted by Pauline Larter on 18/10/2014

    My dad James Donnelly worked at Hepworth and Grandage until about 1958. I always remember meeting him out of work on payday and walking home with him down Wakefield Road to Francis St.

  • Posted by Mark Coulton on 22/05/2014

    I was a student apprentice at Hepworth and Grandage from 1972 to 1977. What they taught me about engineering, work ethic and enjoyment was beyond measure and has stayed with me throughout my life. Grateful thanks to Mr John Pollard and Billy Garrett.

  • Posted by robert usher on 11/11/2009

    Piston ring production moved to Sunderland in the 60's. Rings were cast in either HG10, HG22 OR HG26. The HG10 was a high carbon steel & usually used for top compression rings. HG22 & HG26 were used for oil rings or chrome plated rings. Production lasted until the 90's. I worked in the sunderland factory from 68 until 85 ranging from machine op, planning eng, prod eng & finally design draftsman.

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