EngJW, my best GUESS is that there is no such animal. It isn't listed in Woldman's, nor on any searching I've done. I suspect that whoever put that designation on the drawing may not have had fully accurate information.
So I would recommend checking with whoever wants you to use this material, and ask for clarification. If it is a stainless steel they want, I'd suggest something like Nitronic 60 or Gall-Tough. If it's a P/M product, perhaps something is available in a controlled porosity, oil-bearing grade.
I have never heard of "seez proof steel". It's just a shot in the dark, but maybe they were intending "Stress-Proof". If the component is something that could be made from cold drawn bar, it's a possibility.
How old is "an old drawing"? In the early 80's a product called "stress-proof" steel bar was introduced into the marketplace. This is a free-machining steel with a hardness around 25 HRC. The hardness is obtained by controlled temperatures in the final rolling processes and controlled cooling from rolling temperatures.
This product is sometimes offered as an alternative to heat treated (quenched and tempered) material, but because it is not quenched and tempered and the free-machining additives, it's toughness and ductility properties are not very good.
I turned up one hit for "seez pruf" nuts used on Jeep exhaust manifolds. Our parts are also exhaust manifold nuts. Must be an old trade name or something. Once I get one of these I will see if it is regular steel or stainless steel. Manufacturing claims it is not brass but impregnated steel. Sounds far-fetched. We could convert it to a standard nut and use Never Seize on it.
