Izrael Grunwerg (known as Otto) was born on 15 November 1908 at Kolomyia,  a city now in the Ukraine, but formerly part of Poland.  He was the son of Moses Moshe Grunberg (d.1944) and his wife, Feiga Fani née Rosenheck (1877-1944).  When the political situation in Poland deteriorated during the late 1930s, particularly for Jewish families, Otto came to England.  In 1939, he was living at Hampstead, London, and described his occupation as ‘formerly steel traveller’.   He soon moved to Sheffield, where he worked as a grinder at Viners.  In the early 1940s, he began trading in cutlery.   In 1947, he was naturalised, when his address was Harrison Road, Sheffield.   In 1954, he registered I. Grunwerg as a private limited company, with £3,000 capital.   Otto and his wife, Greta (1908-2011), whom he had married in 1945, were the partners.  The company was established as a manufacturer, merchant, and importer and exporter of all types of cutlery and hardware.  

Otto Grunwerg made his mark as managing director of The Pinking Shear Co Ltd.  Its advertisements in the early 1950s gave the address as 26/28 Wellington Street.   According to Herbert Housley (personal communication to the author), Otto’s partner in Pinking Shear was Mr Bernice Goodman, who was also a buying agent for London wholesaler Castleware Ltd.   Grunwerg’s speciality was shears for the textile trades, which were advertised as made from best-quality forged steel and trade marked ‘PRECISION SANDKAULEN’.  This was a German brand from Solingen.  The Pinking Shear Co did well and its 54 workers presented a clock to Otto and the other managers in appreciation of their efforts (Bradford Observer, 20 January 1956).  Later that year, the firm was absorbed by Mappin & Webb, though Otto remained for a time as manager.  The other directors were Joseph Frederick Robinson (a director at Mappin & Webb), Edward Randolph Footring, and H. M. Oppenheim.  The firm had moved to Australian Works, Malinda Street.  (Pinking Shear Co was eventually liquidated in 1975 and the name acquired by Geo. Wostenholm & Son,)

I. Grunwerg was not listed in directories as a cutler, but as a manufacturers’ agents at 20 Cambridge Street and Leavygreave Road.   However, in 1964 Grunwerg acquired Laurel Works of G. H. Lawrence at Nursery Street.  In 1966, Grunwerg’s share capital was increased to £3,500.  It was still classed as a manufacturers’ agents, but at Nursery Street Grunwerg began the manufacture under license of scalpels, razors, and surgical blades.   Otto’s son, Charles, was the manager; and he was later joined by his younger brother, David.  

By the early 1970s, I. Grunwerg Ltd was listed as cutlery manufacturer.   In 1973, share capital was increased to £10,000.  However, the decline of UK industry combined with import penetration ended Grunwerg’s manufacturing efforts at Nursery Street in the early 1980s.   Laurel Works was later demolished.  Grunwerg moved to modern purpose-built premises at Silversteel House, 29-45 Rockingham Street; and also later occupied the old offices of J. & Riley Carr (file and steel makers) at Bailey Lane.  Izrael Grunwerg, of Brincliffe Crescent, died on 4 January 1980, aged 71.  His burial was at Ecclesfield Jewish Cemetery.  He left £82,856.

Far Eastern cutlery swamped most of the Sheffield cutlery firms, but Charles and David Grunwerg turned the situation to the company’s advantage.  They abandoned manufacturing and decided to import from the Far East.   In particular, Grunwerg in 1990 became a distributor of the ‘GLOBAL’ range of premium Japanese knives.  Grunwerg’s other brand names included ‘Tojiro Senkou’, ‘Rockingham Forge’, ‘Bellux’, ‘Cooler Core’ and ‘Condimates’.  The Grunwergs successfully transformed the company into a wholesaler of cutlery and other catering and kitchen wares.  It had a workforce of about sixty.  In 2019, the Rockingham Street site was obliterated by student flats and the company left Sheffield city centre to relocate to Silversteel Manor in Sheepbridge.  It also opened a London showroom (‘Santuko’) at Great Portland Street.  David Grunwerg retired as managing director in 2021, and ownership of the company passed to his sons, Ben and Adam, and daughter, Anna.  It remained a profitable family-owned business, with sales over £10m in 2020-21.