The most common types of steel include the following:

1. Tool steels - the hard steel of choice for cutting tools. Popular steels in this group include the D2, O1 and CPM series, plus more advanced supercutting steels like M4.

2. Carbon steel - generally made roughly, used where toughness and durability are particularly needed. Often used in survival knives and machetes. It has a sharp edge and is 

relatively easy to sharpen. The trade-off is that it has a low chromium content and is prone to corrosion. The most popular carbon steel is 1095

3. Stainless steel - basic carbon steel with chromium added to make it corrosion-resistant, and other elements added to improve its performance, but at the expense of 

toughness. The most popular types today include 400, 154CN, AUS, VG, MoV, Sandvik and Crucible SxxV series. Note that true stainless steel contains at least 13% chromium.