Alloy 20

It was the one they made, or specified or used after alloy 19?
Del
_{(scampers off to secret cat nest)}

Just a code name but can relate to 20% (19-21) Chromium.

Also refer to Carlson alloy C20.

You may be correct in saying there are a number of "copycats" around. After all, wasn't it the Europeans who stole the march on middle ages China by copying a clock, developing it so that it was a manageable size, thus allowing them to navigate further and develop trade and spin-off industry. As an engineer I have seen, time and again, instances where my designs or concepts have been ripped off - by other companies in some cases, but often by people within my own workplace (more expert in creative legal, financial or contractual dealings). A typical case was when a subcontractor, in league with one of our own contract engineers, managed to get a design award for developing a desing that our contract engineer asked them to fabricate. Does it annoy me? Not a great deal. I know they can copy but they always come back begging when they need something new or have a problem. And I, like a fool, (do any other engineers recognise themselves here?) help them to get out of trouble - again. All any individual needs to do , and it applies to companies as well, is keep ahead of the game. Innovate at a pace that others cannot keep up with. It also helps larger corporations if they have a good legal/contractual infrastructure.

By the way, if I specify Carpenter alloys (or another company such as Haynes or Inco), I do not accept substitutes. I like the idea of getting things cheaper but the equipment I design is used in critical applications. I just do not want to take the risk.

'Guest' is correct, Carpenter originally patented this alloy (patent no. 2,553,330) as Nilstain C-20, it is primarily used in the chemistry industry because of its very good resistance to heated sulfuric acid, better than the stainless steel grades of 18-8. I have an old alloy book which lists a lot of alloys, unfortunately, there is no copy right date in it but from the looks of the machinery pictured in it, I would say the 1940s likely.

The point that I was trying to stress is that, in its evolutionary name change from "Carpenter 20" to "Alloy 20"...........theft was involved.

This is the correct and true answer to the original post