By 1796, Thomas Sansom (1756-1836) was established as a table knife manufacturer in Norfolk Street.  In 1808, he registered a silver mark.  His wife, Martha (1758-1822), bore him a daughter (Anne) and four sons: William (1782-1841), Thomas (1784-1815), Abraham (1786-1838), and John (1789-1859).  The Sheffield Independent, ‘Notes & Queries’, 25 September 1875, provided precise details on their births.  For example, William was born on 29 January 1782, ‘at a quarter before eleven o’clock at night’; John on 24 March 1789, ‘at half past eleven before noon’. 

By 1822, Sansom & Sons was listed as ‘merchts & mfrs of table, pen, silver and plated fruit knives, 23 Norfolk St, grinding wheel Grimesthorpe’.  It became a prominent cutlery manufacturer, which sold the best qualities of table cutlery, pen knives and razors, and occasionally used gold and silver.  William became Master Cutler in 1826;  John in 1834.  The firm had a Royal Warrant as ‘Cutlers to His Majesty [King William IV] and Cutlers Extraordinary to the Queen’.  Evidently, Sansom’s Warrant was a point of rivalry with other ‘Royal’ cutlers – notably Joseph Rodgers & Sons (Sheffield Independent, 13 November, 24 December 1830).  However, in 1833 Thomas Sansom & Sons (‘merchants, cutlers, farmers, and colliers’) was dissolved.  Thomas Sansom was nearing the end of his life (he died on 6 February 1836, aged 80, and was buried in Ecclesall) and a family dispute had arisen (Sheffield Independent, 19, 26 January, 17 August 1833). 

The outcome was that Thomas Sansom & Sons continued at 23 Norfolk Street under Thomas and sons, Abraham and John.  Meanwhile, William formed Sansom, Harwood & Co (with Samuel Harwood) at 36 Norfolk Street.  In 1833, that firm registered a silver mark.  The arrangement with Harwood was soon dissolved – again, it seems, less than amicably – and William continued alone as W. Sansom & Co (Sheffield Independent 28 February, 17, 14 March 1835).  In June 1835, he registered a silver mark.  He was appointed Cutler to the Duchess of Kent and Princess Victoria (Sheffield Independent, 12 September 1835).  William continued to snipe at Thomas Sansom & Sons over the rights to the company name and the Royal imprimatur; and also, with Joseph Rodgers & Sons over the terms of their respective Royal Warrants (Sheffield Independent, 30 September 1837).  In the directory (1837), William took out a full-page advertisement to boost his Royal credentials.  Both family businesses were listed:  Thomas Sansom & Sons at 23 Norfolk Street and William at 36. 

In a decade, the two firms disappeared.  Abraham Sansom died on 21 May 1838.  In the 1840s, John was joined by George Howson and James William Harrison.  He also partnered Edward Hatfield (see Waterhouse, Hatfield), which ended in 1848.  (In 1828, John had married Ann, the daughter of Joseph Waterhouse.)  In 1849, Thomas Sansom & Sons was dissolved, and the assets became the basis for Harrison Brothers & Howson.  John retired to France and died at St Adresse, Le Havre, on 11 January 1859.  His son, John Waterhouse Sansom, became a partner in Sansom & Davenport and Sansom & Creswick (see Thomas J. Creswick).  William Sansom died on 21 February 1841, aged 59.  He was buried in St George’s churchyard, Portobello, where his gravestone (one of the few remaining) also records the death of his son, Thomas William, who died (aged 17) on the following day.  His widow, Mary, continued the business, which won the gratitude of her workers (Sheffield Independent, 24 July 1841).  She died on 5 October 1846 (aged 63), when the company was managed by Peter Rose Dummett and Henry Parkin Badger.  In 1848, that partnership ended, and W. Sansom & Co was sold to Joseph Mappin (see Mappin Brothers).