Sheffield Testing Works

Mentioned in this article on the 1919 Levant Mining Accident:

"A full investigation took place and the caps which were made of faggotted iron were tested at the Sheffield Testing Works was found to be not uniform in quality owing to the method of manufacture."

Grace's guide:

1880 Thomas Nash established an independent testing and experimenting works in Sheffield. This produced accurate work, with the result that the business grew rapidly. He then added a chemical laboratory to the mechanical testing laboratory.

1889 William Cleland appointed manager

1892 Nash handed control of the business to his son Tom

Here's the Companies House entry

For (now London registered) Element Materials Technology Sheffield. Note - list of older names includes the original Sheffield Testing Works, from 1903 when it was incorporated. Orig incorporation doc from 1903 here. From that:

The objects of the Company:

"To carry on the business of general testers of the strength and quality of iron and steel and other metals, iron founders, mechanical engineers, and manufacturers of implements and other machinery, tool makers, brass founders, metal workers, boiler makers, millwrights, machinists, iron and steel converters, smiths, wood workers, builders, painters, metallurgists, electrical engineers, water supply engineers, carriers and merchants, and to buy, sell, manufacture, repair, convert, let on hire, and deal in machinery, implements, rolling stock, and hardward of all kinds, and to carry on any other business (manufacturing or otherwise) which may seem to the Company capable of being conveniently carried on in connection with the above, or otherwise calculated, directly or indirectly, to enhance the value of any of the Company's property and rights for the time being."