There are few things in this world that all nerds can agree on. We may quibble about the virtues of Star Wars vs. Star Trek and get into some pretty heated exchanges over the finer points of ghostbusting technologies, but there’s at least one thing we can all agree on: swords are awesome. Whether you’re a lover of anime, Lord of the Rings, or even DC Comics, the mighty sword is a ubiquitous feature.
If you’re in the market for a sword of your very own, you want to make sure you’re getting a quality blade that will impress everyone in your D&D party. But how do you distinguish such a blade? There are a few specific qualities to look out for.
1. Carbon Steel Construction
The name “carbon steel” is a bit redundant; steel is always carbon-based. But in the world of swords and knives, the term “carbon steel” is commonly used to refer to high-quality steel blades that are NOT stainless steel. If you want a battle-ready blade, stainless steel should be avoided. Carbon steel is stronger and can withstand direct impact. Stainless steel swords are usually shinier, but they’re strictly for show.
The most common types of carbon steel are AISI  (chrome, magnesium, and iron) and AISI 5160 (chromium and silicon). The “xx” in the AISI 10xx designation refers to the actual carbon content of the sword. For instance, AISI 1050 steel should have a carbon content of 50%, while AISI 1070 steel should have a carbon content of 70%, and so on. Japanese samurai swords are commonly AISI 10xx whereas European medieval-style swords are commonly AISI 5160. Because AISI 5160 swords have lower carbon content, they’re among the toughest blades in existence.
2. A Balance of Shine & Matte
If you want a high-quality sword, don’t be fooled by a seductively shiny appearance. A rugged, battle-ready sword will also have some matte qualities along the center and edge. Examine the blade closely, and look for a pattern that resembles waves, water drops, or a steady wood grain. Sometimes this effect can be added for decorative purposes using an intricate etching process, so it’s not always an indicator of quality. However, if the blade looks perfectly smooth and shiny, that’s usually a red flag.
3. Heat Treatment
The challenge with building a quality sword is in ensuring that the blade is hard enough to make an impact but also rugged enough to withstand said impact without snapping like a twig. High-carbon swords tend to be hard but brittle, and low-carbon swords tend to be rugged but with a lower relative hardness. So how do you strike the right balance?
The answer is heat treatment. When shopping for a sword, make sure that the product is heat-treated. This lets you know that the product has both the toughness and the hardness necessary for battle.
4. Tight, High-Quality Binding
If you’re purchasing a traditional Japanese sword with a  , or handle wrapping, always check the binding to ensure that it’s firm and tight. The Tsuka-ito binding is traditionally made from fine cotton or silk, and it helps you to maintain a firm, comfortable grip. If the binding is loose or compromised in any way, it will significantly impact your experience.
Always Do Your Homework When Buying a Sword
If you’re just looking for decorative or model swords, the information in this article might not apply. But if you want the real deal, it’s important to pay close attention to all of the finer details. Inquire about the steel construction and heat treatment, examine the blade and the binding, and don’t be afraid to ask questions. Once you have your battle-ready sword in hand, you’ll be ready to storm King’s Landing and claim the Iron Throne for yourself.
Let's give some examples the first time we use this "xx" designation to make it clear that it's a variable and not an actual designation itself.
Let's briefly define this so those not already familiar with the terminology know which part to look for/at. There are several bound/wrapped/tied parts of Japanese swords and scabbards.