Archive of Collections



Details and Image



TypeModel No.MakerCountryConstruction
Material
DateScale LengthArea of Use
Disk
Steel Hardness Conversions Calculator
FernsEngland
Plastic
est. 1960'sDia. = 12.8 cmSteel Industry

Notes: Used to calculate the hardness of various steel shapes and types of steel


Image 1




Image 2




Image 3