I’ve rolled and drawn a lot of my own small gauge wire before and
had no problems. Recently though I’ve had the need to do some heavy
gauge round sterling wire and am running into an interesting problem.
Any suggestions would be most welcome.
So, I’m starting with 5mm square silver rod and want 2.5 mm round
wire. I do the usual progressive roll-down on the mill to get say a
2.6+ mm square wire and then take that over to the draw bench. The
problem is that as the square wire is rounded off on it’s way through
the round wire plates I get these wicked burrs. The wire comes out of
my mill as the usual square with the corners knocked off so each of
those square edge gets rolled over by the drawplate to produce a
burr, so that’s no less than 8 full-length burrs per length of wire
Of course you need to cut these burrs off before you proceed very
far in the drawing process and that takes a lot of time, at least
doing it by hand the way I have been.
In case anyone is wondering let me be clear: this is not a defect in
the drawing plates (I’ve tried several different plates, some steel,
some carbide). And it’s not a problem with burrs pre-existing on the
milled wire (I’ve checked, several times).
I’ve tried repeated thorough annealings (much more than the wire
itself really calls for), different lubricants (motor oil, wax, soapy
water), larger and smaller draw-down steps, etc and nothing seems to
have much affect. Lots of burrs, lots of nasty work slow-downs and
I’m not a happy camper.
So, what’s the trick here? What am I missing? I’ve tried consulting
the reference books… nothing. I’ve tried searching here at Orchid
… the same. So I plug on trimming off those long, nasty burs but I
do find myself wishing over and over that there was a better way.
As I said, all suggestions welcome.