Hi Gavin,
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Originally Posted by freebooter
I nearly forgot Chris, with your experience with metal, what light can you shed on the old process these old cutlers used for "tempering" of the handle of these brass handled knives. I know much of the light guage brass sheet metal I have used over the years is too flimsy to be of any benefit of a knife handle, what is it that they have done to add strength to these handles.
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I am not sure if I understand your question, but it appears that you would like to know how brass sheet of a given thickness can be strengthened. If so, here it goes:
Brass used by cutlers, gains strength by cold working (hammering, rolling etc) and loses it by being heated (annealed).
Brass sheet, rod and wire is sold in various hardness grades. The hardest and strongest being severely work hardened, whilst the softest and weakest is annealed. As the brass is worked, it gains strength in proportion to the deformation induced by the process.
The trick is to start out with the highest temper that will be able to take the anticipated working. Start out with one that is too hard and the piece will crack. Too soft and it will not be sufficiently strong for the application.
This guessing game can sometimes be simplified by choosing a softer temper and compensating for any lack of strength by increasing thickness or diameter.
As for the old cutlers of the 18th and 19th century, I am not sure how they obtained their brass sheets. I imagine that some may have rolled their own, whilst others must have bought it from a supplier. Be this as it may, the above principles applied then as today.
Cheers
Chris