View Full Version : Best way to ID steel

Ed Tipton
08-31-2006, 10:49 AM
Like most of us, whenever I start a project, it usually begins with a trip to the scrapbox. I almost always find something that looks as though it might just work, but then the fun starts. What is this stuff? High or low carbon? Is this round bar stainless? I wonder if this will harden (which leads me into my next post) You get the idea. I've tried the "spark test", but I'm not sure of what I'm doing. HELP!!

Forrest Addy
08-31-2006, 11:17 AM
First of all, never use mystery metal for anything involving safety or that you deem important or lasting.

Second of all, maintain material ID even to the scrap box.

Third, develop the habit of never mixing materials in your shelves and racks. Have a separate rack space for each then segregate by size.

Fourth, toss all mystery metal you cannot identify.

The spark test is not conclusive but when used with an acid etch, rust test, file test, hardness test, etc some shrewd gueses are possible. Perform the spark test only with a freshly dressed clean grinding wheel in low light against a dark background like the shadow under the bench.

One of the pass/fail observations I perform when entering a shop of any kind is the condition of the stock rack. It might be in disorder but is the material color coded or stenciled or marked in some way for material and condition? Is the scrap box small and tidy or large and confused containing odd and ends of mystery metal? Is mysteriy metal identified as such and kept segregated from stocked material? Are the material invoices available for following material use?

08-31-2006, 12:05 PM
I paint the end of all my steel so I know what the type is.
I use the same color code as when I worked, as I used to have account with them for my material purchases. Never had to worry about being caught by the guards and maybe losing my job as their price to me was what they paid.
I never went to the scrap bin because I still had to pay same price and did not know what I was getting, I would go to the material room foreman tell him what I needed, pick it up later in the day along with 2 paper copies, one for me and one for the guard, they slimply then just deducted from my monthly check. Now being retired I use "Speedy metals" and still use same color chart.

Regards Graeme

08-31-2006, 12:28 PM
Dykem makes thin-line pen markers in various colors. I've got a couple, a yellow one and a red one, that I use to write the i.d. information on barstock.

08-31-2006, 12:57 PM
All my tool steel is stamped on one of the ends. That end faces out. I use magic marker or paint to write on the metal just what it is. 4140, 1118, etc.

09-01-2006, 08:26 PM
I'm waiting to see if it works, but...

We have a contract electronics manufacturer that we use at work. Those in the business have heard of the "RoHS" initiative that has now gone into effect. Basically, it forbids all kinds of materials deemed hazardous from electronics to be sold in Europe.

Well, our CM caters to both civilian and military clients. The civilian clients that sell to the EU have to use a "RoHS" process - that mostly means "lead free". The US military, OTOH, mandates the use of lead and other more "traditional" materials. So our CM has production lines for both, and they can't be mixed.

In order to test for material content, they have a machine that works a little like an MRI machine, but instead of using a magnetic field, it uses xrays. Zap the sample, and the machine reads the resulting scatter and so forth. From that, it can produce a kind of spectral display that shows what elements are present and, if tuned correctly, the percentages of each.

I gave them samples of several types of lathe cutting tools, and asked if they can run them through this process and tell me the composition of my cutters. There are about 5 different samples, and one is a known sample - stellite. I'm very interested to hear the results, and I'll post what I find right here.

Of course, such an exotic (and doubtless, expensive) machine is beyond the reach of the casual machinist, but the service might be a very interesting sideline for someone with access to the machine during the "off hours". BTW, as I understand it, the machine doesn't use "consummables" other than electricity. That means that the expense is the machine itself, and not so much a "cost per use."

I can't wait.


Ed Tipton
09-02-2006, 05:39 AM
I do know that it is common practice to write on or paint the ends of rounds etc to ID the type of metal you've got. My question is this:is the color code standardized? Where can I find a chart, table, or info that would be suitable for putting in my shop for ready reference? Thanks.

09-02-2006, 08:04 AM
No, there is no industry wide standardization for color coding material. Every mill uses their own color schemes.