Introduction: KNIFE FROM a NAIL

About: I am an artisan/teacher. I will post instructables starting from simple ones. Little by little the difficulty will increase but if you followed the previous ones there will be no problem. Yo can see my works...

Forging is fun. Steel needs to be hot forged but iron can be cold forged, needing only to be annealed when hammering has hardened it.
Common nails are made of iron, (or of mild steel in this case you must anneal them when you feel they are getting harder to hammer) ; any nail, around 3 inches long, can be turned into a small knife. Old bent nails cost nothing so you can try and make different shapes at no cost. Annealing means bringing the steel to a red-heath temperature and letting it air-cool.


You need a hammer, a lump of steel for an anvil (a sledge hammer head will do), a stump, a flame, a couple of pliers, and a file.

Step 2: Bend the Nail

1) The blade has to be thinner on the cutting edge and thicker on the back, but the edge that gets thinner becomes longer because the squeezed metal must find space anywayand your blade would bend upwards.
 To prevent it you first slightly bend the blade then hammer the inside of the curve.

2) Blow after blow you will see the blade straightening. The point of the nail gets the right shape by itself if you hammer it evenly.
3) The stake you’re hammering on had better be a bit rounded since you have to “pinch” the edge of the blade.

Step 3: Round Off the Head

4) Now you can round off the head of the nail, hammering it on edge. As the diameter of the head diminishes, a protruding edge develops on both sides of the head.

5) Tuck in this edge bending it down.

Step 4: The Shank

6) Now you flatten the part of the nail between the head and the blade to make the shank. Try and keep the nail's head out of the stake.

7) After flattening it, the shank is hardened: to soften it you must bring it to red heath with a flame and let it air-cool.

8) Now you hold the shank with two pliers and twist it.

9) Some hammer blows on the twist will straighten it. Now you have a small handle with a good grip.

Step 5: Finishing

10) Hammer work is over, notice the colour changes from black where the iron was heated, to blue and yellow. Now you can file the blade to sharpen it and do a bit of filing on the shank.

11) If you want you can hone the cutting edge and go over the rest of the knife with different grades of abrasive paper.

12) Your raw material costs nothing (old and bent nails), forging a small knife is a question of minutes: there's plenty room for experiments with different shapes and sizes. Enjoy yourself!
PS. To see more tutorials on metalwork go to my site

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You could make a drill bit out of the handle design

2 replies

in fact i did, not with a nail which is made of iron, but from a jeweler's burr (+ or - same diameter as a nail).
If I haven't done it yet, (must check- bad memory) I will post an instructable on a drill bit making soon.

cool, sorry for a late reply i lost my login, also, do you think you could make a video for this? the pictures aren't as descriptive, especially in step 2.

You should mention in your text that people should NEVER use a claw hammer (or worse, a hatchet) to forge. A lot of people don't realize that blacksmith hammers are different for a reason. If the hammer accidentally rebounds off the anvil, it can come back and hit you. Especially when working something small, and you lean over the work. With a ball peen or cross peen hammer, you get a black eye. With a claw hammer, you get an eye removed!

This is really cool. I am going to make one as soon as possible.

Could these be sharpened? As I am looking to make a letter opener out of one but the one I made is not very sharp. Can these be sharpened and if they can how?

1 reply

just use a coarse file, an irregular edge cuts (really breaks, tears) better the paper and does not slip.
You will find that a longer blade is more functional than the ones I posted,

Do you have to anneal the nail before hammering because when i hammer mine it doesn't seem to shape. This could be the surface or the nail itself. Any suggestions?

1 reply

usually the iron nails are already annealed. Maybe you are using steeel
nails, they must be hot worked, annealing the will only admit a few
blows before hardening again

I made one today I couldn't be happier with it it is great

I just made mine its pretty cool its not very sharp though but keep up the good work

I call this bad boy the HARBINGERRRR


Hi, I have some very old iron nails, but having some trouble forging/hammering them. They split and splinter - despite being annealed and cooled. Any tips??

made a couple of itty bitty nail knives (well, I guess one's a sword). here they are!

1 reply

I really like your nail knives! They look kind of cute :P haha..

Maybe they are the next best tactical knife in the market. They can easily be hidden and they are extremely dangerous.

My new favorite knife a carpenter, I have 1000's of these just waiting to be made...gonna start this weekend. Seriously, most unique knife platform I've ever seen.

Wow! Incredible. The metal just becomes beautiful! I wonder do you do any hands-on lessons? You are a true artisan - I bet your hands could tell a thousand stories...

1 reply

Ahem... in fact teaching metalworking classes is what I prefer to do.
But I live in Pennabilli, a village in Italy.
happy Easter!