Click here or on the photo for a PDF file.
Everyone knows about “cold rolled” and “stainless” steel. When you want something else you need to order steel by the numbers. 4140, 1215, etc steel. The steel industry uses a standard set of number to tell you all about the properties of a chunk of steel. How hard it is, tensile strength, easy or hard to machine, etc.
When I am looking around on the McMaster-Carr web site (www.mcmaster.com) for a nice piece of steel. The web site sometimes shows me a nice table that does a great job summarizing the different kinds of steel. (See above photo and PDF.) Other times I can get the web site to show me this table to save my life. I forget I need to search on “about steel” or “about tool steel”.