First of all, it is important to note that there is no such thing as a “best steel”. Different steels will perform well in some categories and poorly in others. It is hard to find a steel that is both flexible and holds its edge, for example.

This is why many single-edged swords (such as katanas and ninjatos) are differentially quenched. This technique involves putting clay along the spine of the sword. When it is heat-treated, the spine is more slowly exposed to the heat whereas the blade gets the full hit of heat. The blade hardens (good for cutting and holding its edge) and the spine remains flexible.

Differential quenching allows some swords to achieve the benefits of flex and hardness, but what about steel types in general? What type of steel should you look for in a knife? In a throwing knife? A katana? A medieval sword?

This guide will help educate you so you can make the decision for yourself.

Stainless Steel

Stainless steel is generally a lower-cost steel. You will generally see “wall-hanger” type swords often made out of stainless steel. Stainless steel is very hard and brittle and so it should not be used for actual cutting; however there are some redeeming qualities about stainless steel. Due to the fact that it is “stainless” it requires little to no maintenance. It does not have to be oiled and can easily be brought to a mirror-like finish.

420 and 420HC Stainless Steel

Good all-purpose steel often used for less expensive swords and knives where cutting and function is not a priority. This steel is a bit softer to work with, making it result in lower-cost items but will require more maintenance to keep the edge.

420 steel can be sharpened to a great edge and has decent edge retention and average corrosion resistance.

440A, B & C StainlessSteel

A high carbon stainless steel, quite a bit stronger than 420. Excellent sharpenability, good edge retention, good corrosion resistance. One of the best all-around knife steels, but it is too brittle to be used in a longer sword meant for cutting

Carbon Steel

Carbon steel refers to a steel that contains up to 2.1% carbon. As the carbon content goes up, the steel has the ability to become harder and stronger through proper heat treating, but the more difficult it becomes to weld as the melting point becomes lower and the steel becomes less ductile.

In general, high carbon steel is a good sign of quality materials for a blade, but the more difficult it is to end up with a quality product.

1045 Carbon Steel

1045 is the lower-end of the acceptable carbon steels for battle-ready swords. 1045 carbon steel is softer and easier to forge which means it can be produced more cost-effectively. It can still be heat treated to harden it enough to make for a good cutting steel. If you are just starting out, we would suggest looking for swords made from 1045.

1060 - 1065 Carbon Steel

1060 - 1065 carbon steel is probably the best general purpose sword steel, particularly for Japanese swords. Swords made from 1060-1065 carbon steel will have great flexibility as well as excellent strength and edge-holding.

The down-side is that the steel is more difficult to forge and polish and thus is more expensive.

1095 Carbon steel

1095 carbon steel is very hard steel and very difficult to forge properly. For advanced users, there is a noticeable difference in cutting ability due to how sharp the edge can be made. The disadvantage is that swords made with such high carbon content can be somewhat brittle and may be prone to breaking or chipping. The steel also has a low resistance to corrosion and thus must be cared for carefully. This steel is recommended for highly-advanced users only, but for these people is one of the best steels on the market.

Spring Steel

This steel is famous for its incredible toughness, ductility and its fatigue resistance. It can literally “spring” back to its true form even after being bent or twisted significantly.

5160 Spring Steel

5160 Spring Steel is often used in European and medieval-style swords. When spring steel is tempered properly, it can result in an excellent sword steel due to its flexibility and durability. Careful heat treating of a 5160 blade can produce a hard edge section and a softer core, an excellent characteristic in hacking blades.

Tool Steel

Tool steels have become more and more popular in recent years as they are a great combination of hard and durable and they hold a keen edge better than most carbon steels.

T10 Steel

Formerly only used in knives, T10 tool steel is becoming more and more popular in swords. This steel is extremely durable and has a very high abrasion resistance. T10 steels have a low resistance to corrosion and thus must be cared for and oiled often in order to avoid rust. Great all-around steel, but typically more expensive.

L6 Bainite

L6 was originally developed for the manufacture of circular saw blades. Recently, sword makers have noticed that the incredible hardness, durability and edge-holding capabilities of this steel would work great in swords.

L6 Bainite has high nickel content which gives it excellent resilience and impact toughness. The Bainite phase of L6, achieved by careful heat treatment, is much sought-after in sword blades. It is very expensive to buy a sword made out of L6 Bainite as there are few blacksmiths in the world who can properly forge and temper with this steel.

HWS-1S and Hws-2S Steel

HWS-1s and HWS-2S steel is a proprietary steel made by Hanwei. HWS-1S and 2s steel offers the best edge-holding capability and resilience of any blade ever produced by Hanwei. The differential quenching process is done deliberately to produce a beautiful O-choji hamon as well. The outstanding performance characteristics of blades forged from HWS-1S steel derive from a combination of the careful selection of alloying elements and a complex processing procedure, basically involving the manipulation of the steel’s carbon content across the blade section. This results in a very tough and resilient blade with a hard, highly abrasion-resistant edge.

HWS-2s is very similar to HWS-1s except a little bit cheaper and easier to work with.

Damascus Steel

Damascus steel swords have been growing in popularity after TV subculture has featured many swords forged with Damascus steel. Damascus steel today is made from many different types of steel and iron slices welded together to form a billet. The result is a great-looking sword with a beautiful pattern on the blade, but often a less reliable and less strong blade. Folding does not strengthen steel the way you may have been led to believe; in fact it can actually weaken it substantially through creating imperfections or air pockets.