Bar none, the best metal for sword blades is steel made from bog iron—that which has been found in bogs as apposed to iron which has been mined from the ground—the main reason being bog iron has silicon in it, other irons don’t.

440A steel is a good steel blade in that it offers excellent corrosion resistance. And as soft steel, it has high machinability (easy to work with) and is also easy to sharpen, making it good steel for knife makers.

440C is the highest Carbon steel in this series and has the highest strength, hardness, and wear-resistance than its siblings. This steel is loved by both knife makers and knife users due to its really high corrosion resistance. It also takes and holds a great mirror-like finish longer and requires very minimal care.

Most 440 stainless is easy and quick for manufacturers to make, but rather fragile and unable to hold a good edge. 440C is generally regarded as the best stainless steel for a sword, although another stainless steel, ATS-34, is probably as good or better.

440 steel has a Rockwell hardness of 58, which is considered quite hard….Table 1: Summary of mechanical properties for 440 steel.

While most stainless steels are resistant to rusting, 440 steels are slightly less corrosion resistant. This is the result of its martensitic structure, which increases its hardness but leaves it more open to corrosion than austenitic and ferritic stainless steels.

It is usually heat treated to reach hardness of 58–60 HRC. It is a bearing steel, and used in rolling contact stainless bearings, e.g. ball bearings and roller bearings. It is also used to make knife blades. 440C can be oil quenched to achieve maximum hardness.

The Twilight Sword was the fiery sword used by Surtur. He notably used it to destroy Asgard in the fulfillment of the prophecy known as Ragnarök.

The 440A steel has a highest HRC of 58, which makes it a hard knife with good edge retention. The 440A stainless steel has a great machinability. In Fact in the steel industry the 440A is said to have the best machinability. The 440A has a decent toughness. It has nickel and chromium which makes it one of the toughest low end steel.

Bohler M390 is widely revered as being the best all-around knife steel, which has led top companies to widely utilize it in higher end knives. M390 exhibits excellent edge retention, corrosion resistance, and high level toughness.

440C is a tough and relatively corrosion resistant martensitic stainless steel that maintains a good edge. For many years, 440C was the benchmark cutlery steel, and even today, represents an excellent choice for knifemaking that would fit most people’s requirements.

440A is one of the workhorses of the Sports and Tactical Knife industry. The majority of entry level knives use either 440A, 420HC or AUS-6 steel. 440 is a medium carbon, martensitic stainless steel that is very corrosion resistant and extremely tough that can be hardened to about RC58.