Thank you gentlemen for the references and help on this subject. In the
mailmakers context he had a need to cut strips that were on the order of
.060 in. wide by .030 to .060 in. thick. These would be then drawn through
wire drawing dies for a minimal degree of cleanup.
In his reply to Martin Burgess's reply in Technology and Culture Summer 1960
Dr. Smith sites several of his flat German links as being made from slit
strips that had minimal cleanup from being drawn through dies.
Smith: "...three of the European ones (nos. 2,3 & 5) had been drawn only a
little if at all. These sections showed only a slight distortion of the
parallel lamellar distribution of impurities which characterize a strip as
can be seen in figures 4 and 5, for example. The European wires may have
been drawn through a finishing die, but they had been reduced in
cross-sectional area by certainly far less than 50% after the metal had been
slit or sheared from a strip."
In trying to better understand what minimal drawing might mean in terms of
resulting physical characteristics I have taken both rectangular and square
cross -section strip and hand drawn it in a series of tests to a smooth
circular cross-section. At each stage I also flattened a section of the
wire to see the effect. What I find is that at the start the corners curve
over as forced by the die. (more so on rectangular cross sections than on
square) As expected when flattened this evidence is reduced but not
obliterated. However it is completely eliminated if the wire is drawn to a
true circular cross section. The evidence such as seen on the links of
Wallace A2 maille hauberk would seem to agree with my experiments and Dr.
Smiths analysis in suggesting that thin strips had been cut that were almost
at the final wire size and then required minimal cleanup or flattening. Or
that at most flattening from a square-ish cross-section to a rectangular
one. This is what prompted my interest in any evidence for early slitting
operations as cutting .060 wide strip from a strip of plate is a pain to say
the least using a hand shear. Width control becomes a significant issue.
From your descriptions it appears that slitting would be easier on thinner
sheet stock but the question then arises is there evidence for it early
enough. I have not tried to cut thin strip via a cold chisel but this may
be worth the experiment.
I appreciate the insight and discussion.
Thank you,
Mark
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