John Tonks and Co
of Central Spring and Steel Works, Furnace Hill, Sheffield
- 1919 Advert as manufacturers of springs and spring-washers. Of Daisy Steel and Spring Works, Daisy Walk, Sheffield.
- 1940 Advert. Springs and spring washers
- 1945 Advert. Springs and spring washers
- 1951 Advert. Springs and spring washers. (of Central Spring Works)
- 1960 Advert. Springs and spring washers
Sources of Information
- Mechanical World Year Book 1919. Published by Emmott and Co of Manchester. Advert p
- Mechanical World Year Book 1940. Published by Emmott and Co of Manchester. Advert p209
- Mechanical World Year Book 1945. Published by Emmott and Co of Manchester. Advert p245
- Mechanical World Year Book 1951. Published by Emmott and Co of Manchester. Advert p264
- Mechanical World Year Book 1960. Published by Emmott and Co of Manchester. Advert p130