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.
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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.
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MichaelT1713 days ago

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

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

brian.tagtow7 months ago


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

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.

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

Psykram4 months ago

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

etch a sketch.jpg
segarza Psykram14 days ago

It's not aluminum powder in those devices.

HeroldB made it!22 days ago

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

CopperBarSmelted (5).jpg
chaydgb1 month ago

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.

nrotxn11 months ago

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

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

is it possible to convert this to units by weight? thanks guys happy burning :)

Demented6 years ago
Well getting any sort of fuse is literally impossible for me. Neither can I make my own. So just wondering... could I take apart my kettle and use that heating element instead? I don't suppose there is any sort of limit to that is there?
you can light Thermite with about 4-8 sparklers wrapped together then stick it in and light it.
you would be covered in 3rd degree burns. You wouldn't have enough time to get away, and do you have any idea how hot thermite burns?
i don't know what sparklers you have, where I'm from they are about 20-30 cm they take about 30 seconds to get to the bottom and that is a good amount of time to run away
sparklers make sparks, and when those sparks hit thermite, it burns.

P. S. here they take about 45 seconds to 1:15 here to burn.
but Thermite is int highly sensitive and would take more than a spark
The sparks are not hot enough, and if they are they I consider the unlucky candidate the most unlucky candidate ever.
 about 2000 degrees of the top of my head, but I forget things easily, all I know is it makes light work of an old sky box and the pot used to hold it together
kind of a rhetorical question, but thanks anyway.
you could just short out a battery (attach one piece of wire to both contacts)
 I've heard yo can get old crimbo lights, knock the glass off and stick in things to ignite them although It might not be hot enough, visco doesn't work but visco in a lump of flash powder on top of the thermite does
just roll paper up and douse it in lghter fluid, for most horrid of cases.
Pyro72 years ago
This stuff burns briiiight, real bright. You can feel the heat from a pretty good distance to. I know Hans Gold sells the thermite kit you can buy online at

Havoc you cant use the aluminum filling, a dark jagged flake works best, 3 micron or smaller. Fillings will not have the cache, and spread speed it takes to truly get the full effect. Trust me on this, I use thermite quite a bit for work.
jpoopdog Pyro72 years ago
you need fine powder to get it started, but oits possible to have 75% of the aluminium as shredded foil or small fillings.
tesla man2 years ago
Do you know what the ratio by volume is?
ratio by volume will depend on the density of the iron oxide and the aluminium powder. forr instance, fluffy concrete colouring grade iron oxide might take up 1L/kg (hypothetically) while natural crystaline rust of identical composition and chemical structure, might take up 0.2L/kg
compress that fluffy oxide and magically it is the same amount taking up half the space. same goes for the aluminium. By volume it is impossible to accurately get the ratios correct. My advice is get a rough weight value of a certain volume of your oxide and aluminium, e.g find out how much 500ml wieghs of both, then youll know how many g/mL it is, therefor giving you a crude but still accurate enough ratio of which to mix your thermite from. A bathroom scale might provide you with this weight if it increments in 100g or so

Alternatively go buy a pocket scale from ebay for $3, even the ones from china last for ages.
Hav0c4 years ago
can you use aluminum filling instead of powder?
By "filling" if you mean "filings" than yes they are just a little bit bigger than dust but basically the same thing.
my mistake i did mean filings, thank you
king_zilla4 years ago
How do you convert cups or tbsp. to percentages like that?
it doesnt matter put it i naa barrel and roll it
you realy can't. The percents are by mass, so to convert cups or tbsp to them you would need to use the density of the different materials, but since the materials are powdered, that would be hard to determine..
Killa-X4 years ago
I've been trying to do a copper thermite mixture. I'm having issues with the fuse. I have magnesium ribbon. I took a pen tube, and filled 1cm with copper thermite. I put the fuse in, and put some hot glue around the top to make a seal. I went to ignite it, to find the magnesium ribbon has stopped 2mm above the glue.

Why is this? Its true i didnt sand the magnesium, but i dont think it would do that much difference...I dont thing it being cold/snow outside, would effect that either...Ideas?
I've been working with thermite for a couple months now, but I've been having troubles with an inaccurate mechanical scale (needs a few pounds of weight to register 100 grams). Would anybody know about volume ratios that work well? I'm thinking about doing a 50/50 mix, which visually looks correct compared to what I've seen. I would prefer not to go scale shopping, and I'm not too picky about exact numbers.
so much for safety first lol
jackh944 years ago
I've heard, that a similar displacement reaction to this can be achieved by using aluminium, (obviously german dark, more fun) and silicon dioxide (sand). Has anyone tried this? I don't if it would work.
If someone does try it to see though remember not to breath in the gas produced because I think it reacts with the water in your body and becomes a strong acid.
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