What is Hi-Ten Steel?

Answer 1

This is steel, the high-tensile kind to be exact. Hi-ten steel is pretty light, and decently durable. However, other materials are lighter and/or more durable. The only real advantage of hi-ten steel is that it's the cheapest. If you take a look at the bikes of BMX bike manufacturers, you'll see that their lower-end bikes are made out of steel. This is fine for most people, but if you actually do any EXTREME stuff with your bike, it's not built for performance.