Nichirin sword questions:
1. How big is a Nichirin sword?
Not all Demon Slayers have the same type of Nichirin Sword. The size and shape of each sword depends on the personality of the Demon Slayers who wield it. But only a Hashira can have such a customized sword. Thus most of the Demon Slayer members have the standard Katana style Nichirin swords. So the dimensions would be,
● Approx. blade length 60-73 centimeters
● Approx. total length 91-106 centimeters
● Approx. blade width between 2.5-3.2 centimeters
● Approx. blade thickness around 7 millimeters at the base of the blade

2. What is a Nichirin sword made of?
Demons are not easy to kill. Their only weakness is the sunlight. So the Demon Slayers needed a weapon that could harness the power of sunlight. And this is where Scarlet Crimson ores come in. These ores are mined from the tip of the mountains which are bathed with sunlight all the time. The ore is a special one as it absorbs the sunlight and retains it. Such an ore when used against a demon releases the stored energy and causes permanent damage to them. Not many know of the true origin of this ore or why it can kill demons but undoubtedly this ore is what makes Nichirin Swords deadly.

3. What does a white Nichirin sword mean?
Each Nichirin Sword is unique as it represents the personality of its wielder. And this personality is signified by the color of the Nichirin blade. One such color is White. This is a rare one as white represen The wielder who wields a white Nichirin Sword is found to be of calm nature. They might not get agitated easily but once they do, there is no stopping them. Within the story, only one person had such a blade and it was the Mist Hashira, Muichiro Tokito. He was always calm and collected but when he was against demons, he was unstoppable.

4. What does the blue Nichirin sword mean?
Blue Nichirin sword is the one which signifies Tanjiro's primary breathing style, the Water Breathing style. As we all know the color of the sword also highlights
the users personality, the same can be seen in case of blue sword. In its case the blue color represents a calmness filled with destruction and fluidity. And all of us know that this is truly the case if we see the Water Breathing Style users. Simply take Giyu Tomioka as an example. He is always calm and the movements he makes when against a demon are filled with destructive force and fluidity.

5. What does a red Nichirin sword mean?
Since the dawn of time, the color red has been associated with fire or flame. In the case of the Nichirin sword, this fact holds true. When a Flame Breathing style user holds the Nichirin Blade for the first time, it turns red to represent its property. It represents the blazing personality of the wielder. Fan favorite Kyojuro Rengoku is the owner of such a blade. And his personality, the flamboyant and extrinsic nature is the proof that he deserves such a bright flaming red sword.

6. What does a black Nichirin sword mean?
Most powerful of all breathing styles is the Sun Breathing style. It obtained such a stigma not because it is the mother of all breathing styles but because it was the only breathing style that hurt Muzan, the father of all demons. And the sword that represents this breathing style is the black Nichirin sword. Only two known wielders of this colored sword are found within the story. One is Tanjiro, the main character and the other is the first ever Demon Slayer, Yoriichi Tsugikuni. So regarding the personality of thewielder, much can't be said except that the wielder is one who cherishes all life.

7. What does a yellow Nichirin sword mean?
Lightning is destructive, fast and precise. When it's contained it is harmless but if it is agitated, it will burn everything. And the color that represents this Lightning Breathing style is yellow. This color signifies the fast nature of its wielder. Zenitsu is the user of this breathing style and from his behavior, we can justify the significance of the yellow Nichirin sword. He is timid and anxious. But when he passes out because of this fear, he is an unstoppable force which is lightning fast.

8. How strong is Nichirin sword?
A demon's body is as hard as steel. Any normal blade will break on contact. And even if sufficient force is used, just any weapon can not hurt let alone kill them.
The only weapon which can deliver the killing blow is the Nichirin sword. The ore used to make it, the Scarlet Crimson ore, is a hard one to handle as it doesn't melt easily. So the resulting sword made from such an ore is extremely hard. It can even withstand the blows from brute demons like the Spider Demon Father. But despite this the sword might break if one uses enough force on a single point as seen in Tanjiro vs Gyutaro.

9. Who makes Nichirin swords?
The Scarlet Crimson ore, raw materials for Nichirin sword, is a special kind of ore. It is not easy to handle as it can withstand huge amounts of heat. So the ones who turn these ores into swords are also special ones. They are the best of the best swordsmiths who know the special properties of these ores. The way one handles this ore can determine whether the sword will be helpful in killing demons or not. And this is why the swordsmiths of these swords are protected and cherished. For Tanjiro, his Nichirin sword was made by Hotaru Haganezuka, a swordsmith who is respected even amongst his peers.