Identification of Wrought Iron

Wrought iron is a very pure form of iron with only about half of one per cent carbon. It is tough, malleable, less fusible, and usually has a fibrous structure. Wrought iron is used mostly in ornamental ironwork, such as fences and handrails, because it is welded or painted easily and it rusts very slowly.

Wrought iron is popular for the bold statement made by the products constructed it. With the desire for durability and rustic beauty, wrought iron is making a fashion statement in homes, all around the world. Wrought iron unlike other metals is full of irregularities of the surface, due to being made by hand, each piece being somewhat different. This is the beauty of the products made from wrought iron.

Wrought iron is not like cast iron, it is not brittle, and does not break easily. This is the reason why, wrought iron is considered as more delicate; however, it is found that, years of paint can obscure this. Cast iron is most frequently identified by its repetitive nature, and forms, which could be carved in a wooden pattern, but not made by hammer and anvil.
Identifying Wrought Iron
Identifying wrought iron is sometimes easy and sometimes not. Wrought comes in various non-standardized grades that range from very nearly pure iron to coarse "muck-bar". There are several tests.

1. Spark Test
   When ground the carbon free wrought will throw long sparks with heavy heads and few branches. It helps to have a sample to compare to mild steel on the same grinder because spark tests vary quite a bit in appearance depending on the speed, coarseness and press applied to the grinding wheel. Note that pure iron or very low carbon iron will spark the same as wrought.
   
   
2. Breaking Test
   Take a small bar up to 1/2" square and saw about half way through or a little more. Then bend the bar to break it. The break will show the fibrous grains similar to wood. The better the wrought the finer the grains. In triple refined wrought it may be difficult to distinguish through this test. Compare test to mild steel.
   
   
3. Etching or rust
   Old rusted wrought clearly shows the grains and looks a lot like rotten wood. A heavy etch will do the same. Again, coarse wrought will be easier to distinguish than fine.
   
   
4. Hardenability Test
   Wrought iron does not harden when quenched. Even mild steel will quench hard enough to blunt a good center punch. Note that low carbon steels require higher temperatures than the non-magnetic point to harden. +300°F or an orange heat.
   
   
5. Forgeability Test
   This requires experience but is almost as reliable as the other tests. Experts can tell very low carbon steel from wrought and pure iron by feel under the hammer.