Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 148,470 pages of information and 233,895 images on early companies, their products and the people who designed and built them.
of 138 Southwark Street
of Pioneer Works, Hanger Lane, Ealing, London, W5. Telephone: Perivale 5631/2/3. Telegraphic Address: "Widerstand, 'Phone, London". (1937)
1912 U. H. magnetos.
1913 Solex carburettors.
1937 British Industry Fair Adverts for "Wolf" Portable Electric Tools. Hand and Portable Electric Drilling Machines, Grinders, Screwdrivers, Filing Machines, Blowers. Valve Seat Grinding and Valve Grinding Machines for motor car valves. Car polishing machines.(Electricity: Industrial and Domestic Section - Stand No. Cb.310) 
1937 Electric tool manufacturers. "Boley" Precision Machine Tools. "Wolf" Electric Tools. 
1939 See Aircraft Industry Suppliers
1949 Name changed to Wolf Electric Tools.