Bed of Nails

The science behind the famous trick!

You may have seen your favorite circus performers or magicians perform the classic Bed of Nails Trick… but what is the secret? Using a smaller version of the bed and a clear balloon, you can see the science behind the trick.

Experiment Materials

  • 2 boards - 9.5" x 4.5"
  • 2 wooden dowels (1/2" thick, 10-12" long)
  • 98 nails
  • Clear balloons
  • Adult supervision
  • **Or you can get the kit!**


  1. Start by making your bed of nails as shown in the video. You will need a board for the top that slides on the dowels, and a similar board with the 99 nails hammered through the bottom.
  2. Once your contraption is complete, blow up one of the clear balloons.
  3. Show your audience that the nails are sharp by easily popping the balloon with a leftover nail.
  4. Now, blow up another balloon and place it on the bed of nails.
  5. Put the top board in place and start pushing down on the balloon. You can push pretty hard on the balloon before it ever pops… your audience won't believe their eyes!
  6. At some point the balloon will not be able to take any more pressure and will pop when you push hard enough… that's okay, it shows your audience that you weren't doing anything tricky!
  7. There's no doubt that everyone will want to see this feat again. Take your bows and blow up another balloon.

How Does It Work?

When you pop the first balloon with the nail, all of the pressure is concentrated on one point on the balloon so the balloon easily pops. When you place the balloon on the bed of nails, the pressure points are spread all across the surface of the balloon. 

Just like the balloon, when a person lies on a bed of nails, their body is evenly distributed across the surface of the nails.  The only real danger of being punctured by a nail is if the performer doesn't lie down or get up correctly and pressure points of the nails are concentrated on one area of the body. Now you know the circus secret!