Magnet and stainless steel cookware

With all the attraction-seeking, I stumbled upon a topic concerning the testing of nickel in stainless steel (SS) cookware with a magnet. Nickel (and other toxic metal ions) can possibly leach into food.

Quick jots on nickel:

• SS is an alloy made up chromium, steel iron, molybdenum, nickel and other metals.
• Nickel is magnetic but when added to the steel mix, the changes in its structure (due to the magnetic field) causes the steel to turn non-magnetic.
• Common SS grades:
  18/0   — 18% chromium, no nickel
  18/8   — 18% chromium, 8% nickel
  18/10 — 18% chromium, 10% nickel

• Nickel is added to SS to protect against corrosion and to give SS its glow.
• SS cookware would usually have a magnetic base so that they can also be used on an induction stove, which uses a magnetic field to heat up the cookware.
• If SS is magnetic, nickel is absent.
• If SS is not magnetic, nickel is present.
• The following is said to encourage more leaching:
  - Salty or acidic food stored or cooked in SS
  - Steel scouring pad and harsh abrasive
  - Pitted surface due to extended use

• Austenitic stainless steels like 18/8 and 18/10 are non-magnetic however a small amount of magnetism is produced after cold forming, e.g. bending and rolling.
• SS cookware can be made up of layers consisting of aluminium (or even copper) sandwiched between 18/10 SS, shielded with a polished magnetic stainless steel exterior. This explains why a 18/10 pot or pan can be magnetic.

  Brands that make such cookwares are All-Clad, Emerilware, Dr Weil and WMF.

I have 4 SS pots from WMF, only 2 are magnetic all over, inside and out. Excluding the lid + handles.