Introduction: Instant Caltrops

Picture of Instant Caltrops

In this instructable I'm going to teach you how to make your own caltrops.

Caltrops are an ancient weapon like a metal sandburr. It's a nail with multiple points that has at least one point upward no matter how it lands. They are also called "star nails". This is the quickest way to make them.

Some people consider caltrops a political weapon in this era of wars for oil for vehicle fuel.
If you are such a person you should pursue your ends by peaceful means instead.
Remember Noam Chomsky's advice:
"If you fear the government the proper response is to get more involved in government, rather than less so, because the Government really is the institution that represents you."
Watch the movie "Weather Underground" to find out what some famous political vandals wish they'd done instead.
I think it was Bill Clinton who said, "It's best to conclude that bad policy is caused by ignorance, not malice."

Safety Warnings:
Flying sharp metal will hit you in the eye.
If someone steps on one of these they'll get hurt.

Excellent photos by theinfonaut

Step 1: Nicaraguan Caltrop

Picture of Nicaraguan Caltrop

Caltrops in the Gallery of Heroes and Martyrs in the town of Masaya, Nicaragua.
These look like barbed wire barbs cut off and welded together, but they're much larger than any barbed wire I've seen. These were used in the revolution against Somoza in the late 70's. Nicaraguans threw them onto roads in front of troop truck convoys to delay them with flat tires.
Somoza was a ( yawn, yet another ) U.S. supported brutal dictator.

By the way, a recent issue of Time magazine reported that Nicaragua now has the lowest risk of terrorism in the hemisphere.

Step 2: Chicken Wire Ain't Chicken No More

Picture of Chicken Wire Ain't Chicken No More

Cut off some cross-shaped chunks from the chicken wire using a bolt cutter.
Then cut the ends off again at an angle to make them sharp. Watch out for flying bits of sharp metal hitting you in the eye.

Step 3: A Tripod and a Spike

Picture of A Tripod and a Spike

Bend the sharp wires as shown. You're done!

Be super careful with these nasty things and don't leave them lying around.
These are only to carry in your pouch at the renaissance festival as part of your costume.


TheodoreK17 (author)2017-06-08

Just bend two fencing nails out to a 90 degree angle, then tack-weld them together!

Lokisgodhi (author)2007-10-29

That's NOT chicken wire. Chicken Wire is braided wire in hexagons.

The material shown is Galvanized Fencing Mesh.

jeffconnelly (author)Lokisgodhi2008-03-14

I'm sure you know what you're talking about, but I'd say that most people would call it chicken wire.

smokehill (author)jeffconnelly2008-03-23

At the risk of sounding like a smart-ass, I feel compelled to mention that no one who had ever kept chickens or knew anything about them would call that chicken wire, since it obviously wouldn't work to keep chickens in. Most people who buy or use it call it galvanized fencing, "welded wire," or "hog wire" -- though real hogwire is wrapped, not welded. Most 2x4 wire is used for staking tomato or bean plants, or for keeping idle chompers out of your garden. Baby chicks, or even small banty chickens, would walk right thru this 2x4-inch mesh. As Lokisgodhi points out, you need to ask for the right thing in order to get what you want. The wrapping on these should be done tightly, since more than likely the cheap spotwelds on 2x4 welded wire will probably break somewhere during this process. Homemade caltrops are often made by epoxying four shingle nails together at their heads, as some vets may recall. The OSS made caltrops for use by resistance forces, and issued instructions for making your own from wire or nails as a field expedient to disrupt Nazi transportation.

DamionB (author)smokehill2017-02-17

Your completely right. It is referred to as welded wire or galvanized fencing not even close to "chicken wire"

JonFG (author)smokehill2012-01-06

I have been dealing with wire mesh for a long time.. If you really want to see the variations on wire mesh fencing, inclucing chicken wire and welded wire, galvanized and all the size and mesh variations.. you can check or

DamionB (author)jeffconnelly2017-02-17

Not even the same style as chicken wire. Two totally different products hero.

tigerboy (author)jeffconnelly2008-05-15


Notbob (author)jeffconnelly2008-03-14

I would have to agree jeffconnelly, I would have called that chicken wire too.

yeahh, chicken wire is the hexagonal stuff...

Lokisgodhi (author)jeffconnelly2008-03-14

If you're ordering chicken wire with the expectation of making these, then you're going to be disappointed with what arrives.

NFI (author)Lokisgodhi2008-09-16

Huge "bump", but you're right - that's not chicken wire. I don't know what these people are talking about.

radiorental (author)2006-08-14

"Warning: Some people consider caltrops a political weapon in this era of wars for oil for vehicle fuel. If you are such a person you should pursue your ends by peaceful means instead." It would seem to me that anyone using these for such a purpose would also want to weigh up this 1) Will cause the car owner to go and purchase a new tyre - more consumption. Although I guess the tyre could be easily repaired 2)If more than one tyre is pucntured it would mandate a pickup truck call-out, more gas consumption 3)Very unlikely to change the car owners mind about the use of their car. A more effective method are those stickers "did you know your SUV is causing global warming"

sonaps (author)radiorental2007-12-18

this guy should really learn how to spell the word "tire" in the correct fashion, it isnt hard, just think (referring to radiorental)

AndrewM509 (author)sonaps2016-12-15

Poor Sonaps is the one who needs spelling lessons. In standard international English, "tyre" is a noun describing the external part of a wheel which comes into contact with a road surface whilst "tire" is a verb relating to physical fatigue.

It is quite telling when someone with limited exposure to a language insists that correct usage and spelling be replaced by their simplified version. Learn something about the world Sonaps - get a passport and visit some English speaking countries (ones that would never elect a Trump, Reagan or GW Bush).

JessieTuhr (author)AndrewM5092017-01-30

Off yourself.

Weissensteinburg (author)sonaps2008-01-01

"Tyre" is actually the correct spelling in British English. It's just like "colour".

Lokisgodhi (author)radiorental2012-01-06

You're assuming that the person will care about your opinion beyond the fact that they are inconvenienced by having to remove the sticker from their vehicle. That's probably unlikely to be the case.

Caltrops are minimally destructive device and will cost significantly longer in money and time to repair or replace the tire. They're non lethal assuming one isn't moving at a high rate of speed when you hit it.

The last, more extreme option would be to devise a catastrophic or lethal device, like a cable strung across a thoroughfare or and IED.

jswilson64 (author)radiorental2006-09-21

Doesn't the production of bumper stickers cause global warming? ;-) Better to just leave a note. I particularly like: "Santa knows you're causing global warming."

Lokisgodhi (author)jswilson642008-03-24

Using a schrader valve core remover and taking the core out of all four of the valve stems is rather effective too.

TASKMASTER588 (author)2016-10-08


dread (author)2015-06-22

"remesh" would be heavier duty than this I think, if that helps. You can buy individual remesh "sheets" of 3.5 x 7 ft. The wire is much thicker than this I believe. They are very inflexible and hard, so you need something very tough to cut them. I use a grinder. Their primary use is for strengthening concrete floors and similar flat concrete areas. In the US and Canada one sheet is between $5 to $7. I use it for fencing because it is very strong and very cheap (and vines grow well on it).

walkerwilliam91 (author)2014-05-06

What do cops use for their spikes? Is it made of the same quality as these are? They seem like they could do a lot of damage to tires.

deployed and being deployed

they use spike strips that they spread across roads, these are primitive handheld spikes

pandaboy292 (author)2008-05-16

couldnt you just use a sharpened jack? or a unsharpened jack. it will still hurt but wont bleed.

n0ukf (author)pandaboy2922008-07-07

If you want hurt without bleeding, just scatter a bunch of 1/4" pebbles (I assume you're implying barefoot, since anything that would hurt through shoes would likely draw blood).

ksmith166 (author)n0ukf2015-04-22

or Legos

btackett1 (author)2011-11-03

these can also be used as a project for school if your school has you do a project that requires you to research on something from ancient times

BenEatsNails (author)2010-02-23

 if you can bent it with a set of pliers then a car or even a shoe is gonna bend it.
but this work in bigger scale

cooy (author)BenEatsNails2010-03-04

the caltrops that he describes will not work. however if done on a large scale like you suggest.  I would know this as these caltrops just got me expelled from school by getting back at another student.

btackett1 (author)cooy2011-11-03

lol wow u failed

weldmeshfence (author)2011-03-25

AXHEJAZ (author)2011-02-07

simply awesome! thanks man, i'm going to try to get thicker wires though to make the caltrop stronger!

ninja patrick (author)2010-04-23

wow it is assum
you are briliand
it is so easy and cheap
but is it strong enough?
don't it breack whan a human stand on it?

tsukiyomaru0 (author)2010-04-19

Ah, I knew I'd see something that thought like me... This might work great if you're running from someone that you believe that may want to harm you in any way. Team it up with CD kunai or Shuriken for MASSIVE DAMAGE!

Jesus10555 (author)2006-12-15

lol, if they are only for pocketing at the renaissance festival, why do you have pictures of them situated under a tire, lmao

mazeka.14 (author)Jesus105552008-12-07

what does imao mean?

goeon (author)mazeka.142009-01-18

laugh my @$$ off

seabee890 (author)goeon2009-10-31

??? What does @$$ mean ??

teslafan100 (author)seabee8902009-12-29

@$$ means butt. lol

seabee890 (author)seabee8902009-10-31

just kidding

loppy96 (author)goeon2009-08-04


mazeka.14 (author)goeon2009-01-19


Colonel88 (author)2009-10-27

Put these in your pocket so when someone tries to pickpoket them they go OWCH.

rofus (author)2009-04-26

these are so simple to make. i cant believe i didnt think of this bafore. ty

pudicobar (author)2008-12-08

I guess you could make a potato cannon and fill this stuff to be shot from behind your car... ;-) . BTW, I think those fence staples welded would do more damage,

shadow12952 (author)2008-10-30

good idea

About This Instructable




Bio: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of, manufacturers of "3D Printer" output ... More »
More by TimAnderson:磨刀的技巧Tricks zum Messerschärfenナイフの研ぎ方のこつ
Add instructable to: