What is the Seppa on a Katana sword


Katana Seppa: What You Need To Know

Seppa are like washers. It goes between the tsuba (guard for protecting your hands from the blade) and the handle. This component is very important to make the katana usable and absorb shocks and impacts. While they're seemingly interesting, there's more to them than meets the eye.

What is Seppa (切羽) on a Katana

Katana Seppa

Seppa are thin washers placed between the Tsuka (handle) and the Tsuba (handguard). They act like the bread in a sandwich, securing the Tsuba in the middle and stabilizing it.

Seppa in Japanese is "切羽", it literally means "Cut Feather". This might metaphorically refer to the size of seppa, because it's tiny and light, you might not noticed it at first glance. 

Purpose of Seppa

The main purpose of Seppa, is to tighten the Tsuba, make it more secure and robust. A shifting Tsuba is dangerous to the users during intense combat, Seppa is important to maintain the Integrity of the katana. 

Seppa also acts as a cushion to absorb the shock transmitted to the hand when cutting hard objects, this will better protect the Mekugi (peg) from breaking during intense use. Seppa also conceals the gaps from the bottom of the Habaki and the Fuchi.

Seppa is the second most worn part of the Katana fittings (Koshirae), first is the Mekugi. Since they are made of thin metal plates, they can get bent or deformed when the Tsuba is replaced or when the sword is sheathed.

Material of Seppa 

Most common material for Seppa are copper and brass, in modern days alloy is widely used too, they are easy to work with and resistant to rust. The relative softness can help cushion impacts and shock.

Gold, gold-plated metals, and iron are also used. High-end and exquisite Seppa can be made from silver or even gold. Of course, the more expensive the material used to make the Seppa, the more expensive it will be. We can find pure gold Seppa used in luxurious Tachi koshirae. 

During WW2, Gunto will use Aluminum Seppa. And in case your katana fitting are loose sightly, you can use leather Seppa to adjust it. 

When buying a custom katana, you can let us know the kind of seppa you want for your katana.

Types of Seppa

Based on the size, Seppa can be classified as 3 types:

Oseppa (大切羽): A large seppa, usually made larger to fit the shape of the "tsuba"

Koseppa (小切羽): Smaller seppa, usually two per side.

Sasaraseppa (簓切羽): A thicker seppa with deep grooves, sometimes placed between the Koseppa.

Seppa used on Uchigatana (打刀) and Tachi (太刀). For Tachi koshirae, usually 6-8 Seppa are used, they are a pair of Oseppa, a pair Sasaraseppa, a pair (or two) of Koseppa. 

For Uchigatana, only a pair of Koseppa is enough. 

Interesting Facts About The Seppa

Although the seppa is an important part of the katana, it can be slightly loose especially in low-quality katanas because most manufacturers are using universal size seppa, that might not fit properly. However, there is a workaround: if a seppa doesn't fit well, you can use a punch to squeeze it into place. This issue is less common with high-quality katanas.

Another interesting fact is that Seppa coated in silver or gold can take up to a month to finish. It's up to you to decide if the extended wait time is worth it for the added quality and aesthetic appeal.

Seppa FAQs

Q. How much do seppas cost?
Ans: Mass-produced seppas don't cost that much. They're usually $5 a pair and made from brass or copper.

Q. Are custom-made seppas expensive?
Ans: Custom-made Seppa can cost upwards of $300. The more premium they are, the more they'll cost. Some can even cost about $500.

Wrapping Up

In conclusion, although seppas might be very low-key, they're very important. However, exquisite seppas might not always be worth it. But at least a high-quality one made from brass or copper is a must. Check to learn more katana parts.

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