Ahhh, the allusive spark test. This indispensable tool/test in sorting metals/alloys has been used for at least the past few centuries, along with the magnet test. With the standardization of metals, it can be quite easy to distinguish many types of alloys just by looking at the stream of sparks they throw off (with a little practice of course)… Oh, and before starting the spark test, please be sure you have a large enough sample of metal. If it is so thin that it just melts, then you will not get an accurate spark stream.
The first thing you want to do, is find a grinder of some kind. A bench grinder should be used, as opposed to an angle grinder or the like. Plus, I would rather hold the sample than hold the grinder, and that way I can get a nice steady stream of sparks due to control.I tried writing out good description of the sparks of metal, but the truth is, this info graphic is 100x better than a written description. Here is this amazing pictorial I found in a very old magazine. Source
All of these metals produce very different types of sparks that any shopman should become comfortable identifying. Ideally, everybody should have a small utility box of some sort in their shop or garage filled with samples of different types of labeled metals.When you come across an alloy you need to identify, do a Magnet Test. That will narrow down many of the alloys in your box. Then, cross reference your sample’s sparks with the sparks of your known metals.
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| In 1941, a Detroit Shopman spark tests automotive metal stock for consistency. |
Note worth characteristics:
- Number of Forks, Sprigs is proportional to the carbon content of the metal. The more carbon, the more of these bursts you will see at the end of the sparks
- Color is going to help identify the alloy content. The darkest red sparks will come from nickel, and cobalt, and tungston carbide
- Brilliantly WHITE sparks: Means TITANIUM! The most magnificent sparks I have ever seen are those from titanium. They are incredibly WHITE and luminous!
- NO Sparks means that the metal is non-ferrous. This is particularly good for telling apart stainless steel from aluminum.
{ 17 comments… read them below or add one }
I recently broke up a bicycle rim that I thought was aluminum, but noticed when I was grinding out the steel spoke eyelets that the "aluminum" produced an extremely small stream of orange-ish sparks… any thoughts?
That sounds like a stainless steel spoke, or the very small amount of sparks were from the chrome plating that is on top of the aluminum. Chromium doesn't spark, but the chroming process is actually a layer of nickel, THEN a layer of chrome. The nickel layer is what is causing that tiny stream of sparks, most likely.
Thanks for the question and good luck scrapping!
Your house is valueble for me. Thanks!…
Great post! I was wondering if there are any other colors of sparks…
I know that titanium makes super-white sparks, but I’ve never seen anything other then that.
what is in plastic why it doesnt make sparks?
Seriously? Because its not metal scrap….. Oh Hi guys.. Names Cory.. Down here in the DFW Tex area and scrappin to get thru this xmas slow time for business.. Just want to let everyone on here know how useful this site is.
Hi Cory! I appreciate the support!
I’ve been trying to identify the metal used in computer printer rollers. They appear to be stainless steel, but are magnetic. Spark stream is not clear to me, and I have not been able to find any specs. Thanks for any help.
My guess is that it is nothing more than regular steel. Maybe it has been chromed to prevent corrosion.
Hi there, It is fire season here in Northern Utah, and a lot of the fires are being blamed on gun fire. I am wondering If lead causes sparks? Or copper in the case that the bullets were copper clad?
Wont be the ammo doing it. I say that because I live in Tex and shoot everything from handguns, g3′s, and such.. Alot of shooters down here.. And never seems to be an issue.. Id say its cigarettes and carelessness.
I could imagine if the friction caused the bullet to be hot enough it could ignite the surrounding brush, leaves, or whatever else it may come into contact with. While I haven’t ever looked into the heat of a bullet after it was shot, if it exceeds the temperature it takes to ignite dried leaves and/or sticks I imagine that it would be possible for a bullet to cause a fire in certain climates and conditions.
In this case sparks would not be needed because the correct temperature for combustion could be reached just by being in contact with the hot bullet and not a spark itself. Using this information you may be able to look up some information on whether this is possible or not.
Hi, I would like to know about stainlessteel, do you get stailessteel that sticks to a magnet ??, how do I grade sstanlessteel ??
Hi, i need the procedure for spark test and the comparison chart for that for all grade of steels…
Hello, first I would like to say what a great and useful site this is.
Now I am a scrap buyer. Primarily interested in Ferrous metal, which has no coating (Tin, Zinc, Nickle & Chrome) when I go out to the scrap yards it is unfeasible to run the spark test. Can you please tell me of any method (besides lots of experience) that I could use to quickly identify whether the shredded scrap metal is of the quality it is advertised as. I am interested in scrap not junk. If this information has been provided elsewhere in the site please direct me to it.
Yes, the fastest method of testing scrap materials is the handheld XRF analyzer: