Comparison between Flex-Metal™ and other weights

Flex-Metal® Versus Other Weights:

There are basically three types of weights.

A. Solid- Normally in the shape of bars or rods

B. Particulate- Normally shot or sand

C. Composite- Mixture of material with a dense material in a matrix



Solid weights made of steel and lead bars are the most common. Big advantages are that they are heavy and inexpensive.

Problems with solid metal bars:

1. Exercising with metal bars against the body has the potential to be very dangerous and should be done with extreme care. If you fall or bump into some one the solid metal bars may cause you or another harm.

2. Solid metal bars do not conform to the shape of your body and can cause tissues damage when you move.

3. Solid metal bars can interfere with your movement, and because they do not flex they can block your ability to twist and bend.

4. When you walk quickly, run or jump the solid metal bars move up and down. This jarring motion can cause more harmful impact on the knees, shoulders and spine.

5. Vests made with solid metal bars tend to hike up the torso during many exercise like jumping rope or running. The wearer soon finds the vest has hiked up to his neck and is hitting his chin.

6. You can not do floor exercises such as sit-ups without the bars pressing into you.

7. Lead bars are by their nature toxic and must be handled with care and checked to make sure no lead is leaching out, coated lead can still leach out. Disposing of lead bars can also be difficult.

8. Vest made with solid metal bars must have the bars placed in a locations where you will not bump or press into them. For this reason they can not be positioned uniformly over the body.



Metal bars can be extremely dangerous if you fall and they move around during exercise. Metal bars also block your movement and can not be used comfortably for floor exercises. Shot and sand bags although less dangerous move around and bulge out causing localized high pressure areas which can chafe and bruise, and are also not suitable for floor exercises.



Particulate Weights-- Normally consist of metal shot or other particulate such as sand or limestone

The main advantages are that they are lower cost and safer than solid weights, so long as they do not contain lead shot.

Disadvantages of Particulate Weights:

1. Metal shot settles at the bottom of the bags creating lumps in the vest.

2. Metal shot shifts in the bag when you move. The more you move the more the shot moves around, increasing the impact on your knees, shoulders and spine.

3. When you bend, the lumps press into your body and cause localized pressure. Metal shot does not bend with you, it resists your movement.

4. Floor exercises are often painful due to the lumps.

5. The movement of the metal shot also causes the vest to hike up in the same way as the metal bars.

6. The movement of the metal shot in the bag causes the bag to wear out quickly and leak.

7. Never buy vest that uses metal shot made of lead. As the lead moves against itself it creates lead dust, the dust passes through the fabric easily and this dust is very dangerous to you and especially children. See lead poisoning.

Many vests are made with metal shot such as Valeo’s weight vest and many others.



Composite Weights-- Normally consist of a dense material contained in a matrix of another material. Concrete for example is a composite of small stones in a matrix of mortar. Composites are created to combine the properties of materials. In the case of Flex-Metal® very small particles of iron, which are very dense, are suspend in a flexible polymer matrix so that the resulting material is both dense and flexible. Many composites are often unstable because of the interactions or lack of bond between dissimilar materials. Creating stable composites is both an art and a science. Ironwear® has over 40 years of experience and more than 30 advanced composite material patents. Ironwear® has the knowledge, the experience, and provides a lifetime warranty for its products. Do not be fooled by third party imitation flexible weights now coming out of Asia, they will only cause you trouble.

We challenge you to find better weights.