Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 143,020 pages of information and 229,410 images on early companies, their products and the people who designed and built them.
Makers of engineers cutting tools, of Summerfield Street, Sheffield 11; of Suffolk House, 5 Laurence Pountney Hill, London, E.C.4.
1913 Company formed: Sheffield Twist Drill Co
1923 London office in Mansion House Chambers, 11 Queen Victoria-street, E.C.
1937 Small tool manufacturers. "Dorclax", "Dormer", "Dormerex" Twist Drills. 
1940 Advert for Dormer twist drills. 
1945 Advert for Dormer twist drills and small tools. 
1947 Public company.
1961 Manufacturers of "Dormer" twist drills, reamers, end mills, milling cutters, taps and dies, and machine tools. 1,250 employees.