Magnetism not desired while modifying a stainless steel rod
this is especially common in low alloy stainlesses such as 301 or 303 stainless (they are just barely "stainless" in that they are only about 12-13% chrome). less so on higher alloy 304 or 316 (18% chrome 8% nickel) but even they will do it, just to a lesser degree. Some alloys are specifically designed for lots of cold work like alloy 321 or 347 and they tend to exibit much less of this but they'll still do it. bending changes some of the crystals from Austenite to Martensite which is magnetic. Annealing after bending will return it to Austenite.
We had a magnetic sensor we designed that used (very) small stainless screws to mount the PCB and we discovered that the screws were magnetic enough to make the sensors unreliable so we ended up having to switch to Beta titanium screws to eliminate the magnetism. (brass was too weak, the heads twisted off too easy.)