Introduction: Thermite

Picture of Thermite


Quick explanation of thermite:

A mixture of iron oxide Fe2O3 (rust) and aluminum powder. When it is ignited the aluminum powder reacts with the O3 part of the rust in a highly exothermic reaction, the resulting product is molten iron.

Thermite is commonly used in welding, because the molten iron has the ability to seep into cracks in metal. It cal also be used to melt through things as shown in an episode of Brainiac and the movie The Sixth Day.

I have made thermite a few times, but never in large enough batches to burn through anything significant. Aluminum powder is hard to come by and I never had a good enough reason to use what little powder I had.

Step 1: Materials

Picture of Materials

All materials can be found here or on E-bay. You can either buy and mix the chemicals yourself or buy premade thermite from unitednuclear.

1. Iron oxide
2. Aluminum powder
3. Magnesium ribbon or thermite ignition mixture

For a more exotic mix you may also want to buy:

4. Barium Nitrate
5. Sulfur
6. Dextrin

Step 2: Mix

Picture of Mix

Mix 76.3% iron oxide with 27.3% aluminum powder to make thermite.

To make the military version Thermate create a mixture of 68.7% thermite, 29.0% barium nitrate, sulfur 2.0%, and dextrin 0.3%.

Step 3: Ignition

Picture of Ignition

The safest container to hold the thermite while igniting it is a terracotta or ceramic plant pot with a hole in the bottom. Place a tissue or coffee filter on the bottom of the pot to prevent the thermite from spilling through. Put the thermite in the pot, and then when it ignites it will burn through the paper spilling molten iron onto whatever is underneath.

Thermite requires extremely high temperatures to ignite (about 4000 F). Ignition can be achieved in multiple ways.

Magnesium ribbon, although unreliable, is still the most popular way to ignite thermite.


Thermite ignition formula sold on unitednuclear

A mixture of Potassium permanganate and glycerine will undergo a reaction that can provide enough heat to ignite thermite.

Allow yourself at least 10 seconds to get the hell away from this stuff, especially if you made Thermate.

Step 4: Safety

Picture of Safety

Thermite burns very hot. It is virtually impossible to extinguish. Do not pour water on it because it will not extinguish it and it give you steam burns in the process. If you are having this burn through something put a bucket of sand underneath it.

Only do this outdoors in a completely nonflammable environment.


MichaelC726 (author)2017-06-27

Reading about all these different mixtures, can any of them be made in a weak enough mixture to 'paint' on wood in a simple design that would burn or etch the wood just where it is painted on.

XavierP20 (author)MichaelC7262017-09-21

Use a soldering iron at a low setting, this will allow for greater precision as well.

miyagisan (author)2017-03-03

al foil and rust will produce the same product

Trerstand69 (author)2017-02-10

Is the thermate by weight because the ratio does not equal 100 percent either.

Supertux (author)2016-12-05

Whats the ratio with copper oxide?

sfjohnson73 (author)2016-07-08

I use this to burn stumps, and it entertains the children. x >

DouglasC67 (author)sfjohnson732016-09-27

Can you give any info on your stump burning experience? Just received the ingredients (pro grade rusty and aluminum powders), and have 26 acres of nasty stumps... Any info is appreciated!

sfjohnson73 (author)DouglasC672016-09-28

It works well with getting the stumps burning. The more product that you use,the faster the stump is consumed. Dry pine stumps burn the best. It will not make the stump disappear instantly but it is faster than charcoal and more fun than digging! What ever you do, PLEASE do it safely. Thermite is hot!

Koopskid8 (author)2016-07-19

is it radioactive?

fatcat360 (author)Koopskid82016-07-30

no it isnt

chip123 (author)2009-02-08

sorry to be a smart arse, but the percentages of the mix add up to more than 100%. if you mix 76.3% iron oxide with 27.3% aluminum powder, then you get 103.6% thermite. this doesnt make sense to me, so could you explain it a little please. thanks

M4industries (author)chip1232009-04-19

I saw that too!

jmeister15 (author)M4industries2009-06-04

Were you directed here by one of mythbusters episodes with thermite? I was!

Mr. Cowboy (author)jmeister152009-06-04

I was too

MaxS97 (author)Mr. Cowboy2016-05-17

Cowboy does this really work

MaxS97 (author)Mr. Cowboy2016-05-17


chip123 (author)jmeister152009-06-04

believe it or not, no. Ive never watched mythbusters

jmeister15 (author)chip1232009-06-05

I love the ice thing! Ive seen almost every episode! Wensdays at 9!

M4industries (author)jmeister152009-09-28

In Eastern stations it used to be, but now its at 8 for some reason. I hear the next myth is on Golf Balls and if the dimples affect flight. it was in a Pop Mech article about the Mythbusters.

santy22 (author)chip1232009-03-17

he just wants to get fancy-ish woth that. mix 75 and 25. also, you can do aluminium powder grinding or blending aluminium paper!

jmeister15 (author)santy222009-06-05

how would you recomend getting the alunimum powder and the iron stuff?

Sdanderson222 (author)jmeister152016-05-01


Bodragon (author)chip1232015-11-12

It doesn't make sense because it's 76.3 : 23.7 (NOT 27.3)

MisterShotgun (author)chip1232009-08-20

He switched the 7 and the 3 in the aluminum powder percentage. It should read "76.3% Iron Oxide" and "23.7% Aluminum Powder."

chip123 (author)MisterShotgun2009-09-09

at makes sense. thanks

speedlimit55 (author)2016-04-05

The debate over Fe2O3 to AL ratio is 80:27... both materials are available though Amazon or Ebay. Other sites offer the materials by the tonne...The ration is by weight. I am mixing 800 grams to 270 grams.

I'm using a 3 inch "fuse" of magnesium in my first attempt... had to get a torch (as in a burning torch) to ignite the fuse. Once I go with that I will also attempt using nichrome wire off a lantern battery, a fireworks igniter off a lantern battery and a final test of potassium permanganate with glycerin. Once I verify the ignition system that works best (safest) I'll add the thermate materials to the mix and update.
For a "hotter" burn I've read that using CuO2 or other oxidizers is better than Fe2O3. Also using different more reactive metals in theory makes it hotter but getting too reactive make storage unstable both from a reactive view and shelf life.

gokahnd (author)2016-03-11

ẨnS8 (author)2015-12-25

does anyone here because breaking bad ?

Mateco (author)ẨnS82016-01-30

oh yes.

Psykram (author)2014-11-04

Need Aluminum Powder but the Mad-Science shoppe is closed?

TonyM87 (author)Psykram2016-01-17

Sorry, but that Breaking Bad episode where Heisenberg makes thermite from the contents of an Etch-A-Sketch and then uses it to burn through a lock was conclusively debunked by Thunderf00t on Youtube. You don't don't need an Etch-a-Sketch anyway. Just get the stuff from Ebay.

ZacharyB4 (author)Psykram2015-03-29

and you are the kind of person that would die if they ever tried to make meth

ChristopherL68 (author)2015-12-26

Um. Yes, it is aluminum powder.

Are you thinking of Wooly Willy, which uses iron filings and a magnetic wand?

knoxarama (author)2009-12-02

now, how to you mix 76.3% with 27.3% of anything? Is 100% not a limitation here? please explain how to get 103.3%

Bodragon (author)knoxarama2015-11-12

76.3% to 23.7% (NOT 27.3%)

Archive555 (author)knoxarama2010-01-17

Anywhere between 3-1 to 3-2 ratio will work, just play around with it a little.

mmm_chewy (author)Archive5552010-01-18

3:1 iron oxide to aluminum by weight

Hot Schnell (author)2015-04-25

What if you mixed the Thermate with magnesium powder? Is that stable? The U.S. Army manual 'Improvised Munitions' instructs to mix magnesium powder with potassium permanganate for storage in a tightly sealed container. Maybe magnesium and potassium permanganate powders can be mixed with Thermate. A match or glycerin would ignite the potassium permanganate, and even the magnesium. Then the whole batch is ignited.

Hot Schnell (author)2015-04-23

What if I rolled cotton string in a mixture of black powder and magnesium powder, and maybe potassium permanganate too? I read that the military stores magnesium mixed with potassium permanganate. I don't know if either would be stable mixed with black powder. I'm trying to figure this out myself. I think a mixture of at least two of the three would work. I would then run the string through a small vial of clear nail polish to make it waterproof. What do you think?

MichaelT17 (author)2015-03-14

Using black iron oxide Fe2O3 and and Al (3Fe3O4 + 8Al --> 9Fe + 4Al2O3 + heat) it's 76.3% iron oxide, and 23.7% al by weight

MichaelT17 (author)MichaelT172015-03-14

Using RED iron oxide (Fe2O3+2Al -->2Fe+Al2O3+heat) it's 74.7% iron oxide, and 25.3% al by weight

brian.tagtow (author)2014-08-04


MichaelT17 (author)brian.tagtow2015-03-14

Using black iron oxide Fe2O3 and and Al (3Fe3O4 + 8Al --> 9Fe + 4Al2O3 + heat) it's 76.3% iron oxide, and 23.7% al by weight

boudreau-inventor2 (author)2011-03-27

I don't really know much about thermite. What is the difference between the military version and the regular version?

Military version ignites easier, and spreads easier with more outgassing.

JoeA9 (author)boudreau-inventor22015-02-03

How hot it burns. The military version burns hotter and faster.

HeroldB made it! (author)2015-03-05

It comes from a chemical supplier like US Halogens to get the best results. Some aluminum and iron oxide you find online give you crumby yields. Try a reputable company like or check the products or merchandise pages. Here's a bar with slag we made from their aluminum powder / copper oxide mix

chaydgb (author)2015-01-29

You can also use sparks from ferrocerium 'flints' to ignite thermite. It's a bit tricky trying to aim the resulting sparks into the thermite mixture but a good substitute if you don't have any magnesium or sparklers.

nrotxn (author)2014-04-05

If you like this you should check out Thermite Arts on kickstarter and on etsy. They have thermite kits on etsy.

MandalorianMaker (author)2014-03-12

instead of iron oxide powder u can use copper powder for a explosive mixture

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