Probably a fairly niche question,but I figured what the hell, I 'd ask.
So I was doing some straightening up and sorting away of boxes and came upon on old Oster stand mixer, with a meat grinder attachment. I have been considering trying my hand at sausage making. But the dies were all black and nasty looking. I decided to try to clean them. Assuming it was rust based I tried Barkeepers friend, then Naval Jelly. It really did nothing noticeable to the coating, So I grabbed a wire brush and started scrubbing. As I got a piece of one section cleaner, I noticed the color was more of brass color than a carbon steel or stainless steel one. But not quite a standout brass color. The are also pretty strongly magnetic. I know brass is little weakly magnetic, but these grab and hold to a fridge magnet.
So before I make any more attempts to clean,and possibly damage, I’m curious if anybody has an idea what they really are. Did they make those things from Brass over steel, in which case i am dealing with a heavy tarnish. Or are there kinda brassy looking Steel alloys?
In looking at Oster meat grinder plates photos on google, most of them are clearly stainless steel, while some of them are black. Are you sure you aren’t trying to remove a beneficial coating applied by the manufacturer?
To answer your question, I can see no legitimate reason to use brass plates for a meat grinder. If a magnet attaches to it, it is almost certainly steel, perhaps a martensitic stainless steel. There are some types of stainless steel that will have or develop a straw color, but I would not expect to see those in a meat grinder.
Meat-grinder amateur here. Can’t think of why brass would be used at all, but then again, fancy dry pasta extruders always are proud of their brass orifices.
(I can’t think of the right word at the moment. Orifices it is.)
The colour could be an artifact of tempering of a steel die after hardening (although unusual for it to survive a long time, I guess) - see colour chart here:
Brass is not magnetic in any sense that a magnet will noticeably stick to it - brass alloys are normally not ferromagnetic at all, but apparently there are some marine alloys that have a small amount of iron in them.
yeah - extrusion of pasta is fairly gentle compared to meat grinding - in a Spong type meat grinder/mincer, there is a star-shaped blade with its flat side running directly upon (and pressing hard against) the inside surface of the die plate - brass would wear pretty poorly in that situation, I think.