>>>
>>>There are some other puzzling things about it too.  Like what is
>>>"shear steel?"
>>>
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Until 1742, producing steel was a difficult task. The quality of the steel
was often unreliable. The steel was made by heating iron bars which were
covered in charcoal. The heating was continued for up to a week. The
material produced was called blister steel.
Blister steel was then turned into shear steel by wrapping blister steel
bars up in a bundle and then heating them again before forging the bundle.
The heat and the action of the forge hammer welded the rods together as they
were hammered to the size required. This shear steel was used to make
razors, files, knives, swords and the other steel items for which Sheffield
became famous.

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Basically they would surface harden the skins and the weld the bundle
to disperse the carbon throughout.

cheers,
greg