Maytag Snow 5 Experts on audio sound say that steel should not be used for audio connections of any kind. The speaker terminals I planned to use for my new speaker were made of brass, but the securing nut and the tab for the internal speaker wire were both made of steel, as confirmed by a magnet. I found these knurled nuts online and took a chance. They are brass, as advertised, and very well made. The threads are cut very well and mate perfectly with M4 screws, as the speaker terminal uses. The knurling makes it very easy to hand tighten the nuts very tight, so I am looking forward to using them. With 50 minimum purchase, I will have a lifetime supply unless I go into manufacturing, but the value is still worth the price.