Japanese Cast Iron Teapot & Tetsubin: Iwachu, Oigen, Nambu

Last updated: 2026-10-22.

TL;DR

A Japanese cast iron teapot and a tetsubin are not the same thing. A tetsubin (鉄瓶) is an iron kettle for boiling water; a cast iron teapot (tetsu kyusu, 鉄急須) is enamel-lined inside and is for steeping tea, never for the stove. Most of what is sold as “Nambu tekki” comes from Iwate Prefecture, from makers such as Iwachu (Morioka, since 1902) and Oigen (Mizusawa, since 1852), plus small Morioka workshops like Kamasada.

• Colorful teapot for loose-leaf tea: an Iwachu enamel-lined tetsu kyusu.
• Kettle for boiling water: a tetsubin from Iwachu, Oigen or a Morioka craftsperson.
• Everyday iron cookware: Oigen pans and pots.
• Collectible: a signed, boxed vintage tetsubin from Morioka or Yamagata.

As of October 2026, this guide covers the main Japanese cast iron makers, the difference between a tetsubin and a teapot, how to read Japanese listings, and what to check before you buy a heavy iron piece from Japan.

Japanese Cast Iron Makers at a Glance

What Is Nambu Tekki (Nambu Ironware)?

Nambu tekki (南部鉄器, also written Nanbu tekki) is cast ironware made by members of the Iwate Nambu Ironware Cooperative federation, which joined the Morioka and Mizusawa (Oshu) casting cooperatives in 1959. It was designated a national traditional craft on February 17, 1975. The two centers have different histories: Morioka casting grew under the Nambu domain from the early 1600s, when the lords invited kettle makers to produce tea-ceremony kettles, while Mizusawa traces its casting back to the Heian period and was long known for everyday pots and kettles.^[1] Both use the Nambu name today.

The craft’s best-known finishing step is kanakedome (金気止め): after casting, a kettle is heated in a charcoal fire at about 800–1,000°C to form a magnetic oxide film that slows rust — a technique credited to Nambu ironware.^[1] Besides kettles and teapots, Nambu tekki crafts include pans, pots, trivets, wind chimes (furin, 風鈴), candle stands (a Japanese cast iron candle holder), a hot sandwich maker and the iron ball or “egg” (鉄卵) that some cooks drop into a pot.^[1]

Tetsubin vs Cast Iron Teapot vs Kyusu

Outside Japan, enamel-lined cast iron teapots are often called “tetsubin”, but in Japanese they are tetsu kyusu, iron teapots. Heating one on a stove can break the enamel coating. A true tetsubin is a kettle with a spout, lid and an overhead handle, used to boil water for tea; small ones hold around 0.5 litres and large ones about 5 litres.^[2] A kyusu (急須) simply means teapot, and in common use a ceramic teapot with a side handle (yokode kyusu); Tokoname ware is especially known for them.^[3] For ceramic kyusu, sencha and matcha makers, see our Japanese tea brands guide.

Tetsubin History: From Tea-Ceremony Kettles to Iwachu

The tetsubin probably grew out of the spouted kettles already used in the tea ceremony, and spread with sencha, the leaf tea that became popular in Japan from the 17th century; by the 18th century iron kettles were a standard household tool, and by the 19th century they had become elaborately decorated status pieces. Its closest relative, the yakkan, is a copper kettle — so a “copper tetsubin” is really a different vessel.^[2] In Morioka, the Koizumi family of kettle makers was hired by the Nambu lords in 1659 to make tea-ceremony kettles, and the third-generation Koizumi Nizaemon is credited as the founder of the Nambu tetsubin; in 1908 the eighth Koizumi Nizaemon demonstrated kettle-making for the visiting crown prince, which helped revive the trade.^[1] Koizumi tetsubin and other old Morioka family names still appear in antique listings.

Handmade vs Factory-Cast Japanese Iron Kettles

A handmade Japanese iron kettle is cast in a sand-and-clay mold made for that kettle, patterned by hand while the mold is still damp, then fired; the full process can take close to two months.^[1] Iwachu’s traditional handmade kettles are limited to roughly 160 a month, while its automated line makes everyday teapots and cookware.^[4] For a handmade tetsubin, look for a named craftsperson, the maker’s seal and a signed box; Kamasada’s third-generation head, Miya Nobuho, is one of the Morioka makers whose handmade kettles collectors search for by name.^[7]

Common patterns: arare (hailstone dots, called hobnail in English), hira arare (flattened arare), kikko (tortoiseshell hexagons), sakura, dragonfly and plain surfaces. A traditional Japanese cast iron teapot or tetsubin with a hobnail texture is the classic arare design.

Iwachu: The Japanese Cast Iron Teapot Most Shops Sell

Iwachu (岩鋳) was founded in Morioka in 1902 by Iwashimizu Suekichi. In 1967 it became the first iron casting works to automate its shop floor, and in 1990 it began making colored Nambu ironware — a project that started with a French tea retailer asking for colorful teapots. Its colored teapots have an enamel-lined interior, and in many European shops Nambu teapots are simply called “Iwachu”. It also makes traditional black tetsubin, cooking pots (some induction-compatible) and decorative pieces; its Morioka factory shop and museum are open to visitors. Iwachu products and Iwachu kitchenware therefore range from inexpensive pans to handmade kettles.^[4]

Search for Iwachu teapot listings by pattern: arare (hailstone dots — a hand-made kettle can carry around 3,000 of them), sakura, dragonfly, bamboo or plain. Capacity is listed in litres (容量). Cast iron teapots often come with a mesh strainer that fits inside, so check it is in the photos.^[2]

Oigen: Nambu Iron for Everyday Cooking

Oigen (及源鋳造) began in 1852 in Mizusawa, now Oshu City, as the Oikawa Genjuro foundry and became Oigen Foundry Co. in 1947. Its catalog covers iron pans, pots, rice pots, tetsubin and iron teapots, and it has worked with outside designers, including a Palma series by Jasper Morrison.^[5][6] Search Oigen for a cast iron frying pan, grill pan, pot, rice pot or outdoor cookware; its kettles are a sound choice if you want a tetsubin built for daily use rather than display.

Kamasada and the Morioka Workshops

Kamasada (釜定) has its shop and workshop in Konyacho, the old merchant district of Morioka. It was founded in the late Meiji era by Sadakichi, who branched off from the family’s kettle shop; the name joins kamaya (kettle shop) and Sadakichi. Today it is known for clean, modern ironware — kettles, trivets and a much-copied Nambu tekki bottle opener — alongside traditional tetsubin.^[7] Production is small, so new pieces sell out and the secondhand market is the realistic route for overseas buyers.

Morioka also has signed kettles by certified traditional craftspeople. These usually come in a wooden box signed by the maker (共箱, tomobako); the box, the maker’s seal on the kettle and the lid all affect price.

Yamagata Cast Iron and Kikuchi Hojudo

Iwate and Yamagata are the two prefectures best known for tetsubin and iron teapots.^[2] Yamagata’s oldest name, Kikuchi Hojudo (菊地保寿堂, founded 1604, also sold abroad under the WAZUQU brand), stopped operating on August 31, 2026 and began preparing a bankruptcy filing, according to local reports.^[8] Its kettles and pots are now available only secondhand; expect listings to rise in price.

Vintage and Antique Tetsubin: What to Check

• Leaks: ask whether the kettle has been filled with water (水漏れなし = no leaks).
• Rust: light rust inside a tetsubin is common (錆あり); deep pitting or holes are not repairable at home.
• Lid and handle: original lids matter for value; a mismatched lid is common on old kettles.
• Signature and box: a cast seal and a matching signed box (共箱) support attribution but are not proof of it; compare with sold listings for the same maker.
• Induction: old kettles are not marked IH-compatible; only modern pieces labeled IH対応 should go on an induction hob.

We do not verify makers’ marks or vouch for condition, so choose sellers with clear photos of the inside, base, lid and signature.

Reading Japanese Cast Iron Listings

Using a Tetsubin vs a Japanese Cast Iron Teapot

Using a tetsubin: fill it with water, heat it on a gas burner, charcoal or (only if marked IH対応) induction, pour, and empty it while warm. Japanese tea kettle stovetop use is what an uncoated, unlined, unglazed tetsubin — a tetsubin without enamel — is made for. Using a Japanese cast iron teapot: warm it with hot water, add leaves to the strainer, pour boiled water in from a separate kettle, steep and serve; keep it off the flame.

Are Japanese cast iron teapots safe? Used as intended — the enamel-lined teapot off the heat, the bare kettle on it — yes; stop using an enamel teapot if the lining is chipped or cracked, and ask the maker. The benefits people cite for a Japanese-style cast iron teapot or kettle are heat retention and, for bare iron kettles, water they say tastes softer; we make no health claims for iron cookware, including the iron ball or “iron egg” that some cooks drop into a pot.^[1][2]

Care Basics

Follow the maker’s leaflet for your exact piece. In general: do not boil water in an enamel-lined teapot; empty a tetsubin after use and let residual heat dry it; avoid scrubbing the inside of a tetsubin, which removes the protective layer; and keep cast iron pans lightly oiled. Iron is heavy and brittle: a dropped kettle can crack.

Tetsubin maintenance and a rusty tetsubin: cleaning a tetsubin means rinsing with hot water only. Light rust spots and a mineral patina (scale) inside are common on used kettles; deep rust or pinholes that leak are not a home fix. Tetsubin restoration by a foundry is possible for valuable pieces — Oigen, for example, takes repair consultations (修理のご相談) on its site.

How to Buy a Japanese Cast Iron Teapot or Tetsubin From Japan

1. Search in Japanese: 岩鋳 急須, 南部鉄器 鉄瓶, 及源 フライパン, 釜定 鉄瓶, 鉄瓶 共箱.
2. Check weight and size: iron is heavy, and international shipping is charged on the greater of actual weight and volumetric weight (length × width × height ÷ 5,000) of the box the warehouse uses.
3. Protect it: package reinforcement starts at ¥100 for parcels up to 2 kg (¥200 for 2–5 kg), with box replacement and extra outer padding as add-ons.
4. See it before it ships: unboxing photos (¥500 / ¥700) let you check the lid, inside and enamel at the Tokyo warehouse.
5. Consolidate: combine a teapot with tea, cups or other purchases to share one shipment.

Shipping damage in international transit is compensated up to the international shipping fee paid, and must be reported within 24 hours with the order number, photos and a full unboxing video; damage caused in our warehouse is refunded at the purchase price. OneMall buys from Mercari, Yahoo Auctions, Rakuten, Amazon Japan and other Japanese stores via LinkBuy; items that need a lottery entry, purchase limit, Japanese identity verification or a merchant account cannot be purchased.

Service fees are ¥300 per item on most marketplaces; from ¥200 per item on Yahoo Auctions and LinkBuy. The first six orders consolidate free; each additional order costs ¥100. Storage is free for 90 days after arrival (30 days after consolidation). Payment is by Visa, Mastercard or PayPal, settled in USD.

US buyers: since August 29, 2025, US-bound parcels of any value go through customs and pay applicable duties, taxes and fees — the $800 de minimis exemption no longer applies. OneMall currently ships to the United States by ECMS and DHL; the live quote at checkout shows which lines accept your parcel.

Browse Iwachu teapot listings or Nambu tetsubin listings, pair them with matcha tools from our matcha sets guide, and compare the best Japan proxy services and the cheapest Japan proxy options by total landed cost.

Frequently Asked Questions

What is the best Japanese cast iron teapot brand?

For colorful enamel-lined teapots, Iwachu is the most widely sold. For everyday iron kettles and cookware, Oigen. For a small-workshop or signed piece, Morioka makers such as Kamasada. Choose by use first: kettle or teapot.

Is Iwachu a good brand?

Iwachu is one of the largest Nambu ironware makers, founded in 1902, and its teapots are widely sold abroad. Quality and price vary by line: factory-cast colored teapots versus handmade kettles.

Is Japanese cast iron good?

Nambu tekki is a designated traditional craft with its own rust-slowing kanakedome finish. As with any cast iron, a good piece depends on the maker, the line and how it has been used.

How much is a cast iron kettle worth?

It depends on maker, age, signature, box, condition and whether it leaks. Compare sold listings for the same maker and size on Mercari and Yahoo Auctions rather than asking prices.

What sizes do cast iron kettles come in?

Cast iron kettle sizes run from small pots of around 0.5 litres to large kettles of about 5 litres; capacity is listed as 容量 in Japanese listings.

Can you boil water in a Japanese cast iron teapot?

Not in an enamel-lined teapot (tetsu kyusu) — it is for steeping only. Boil water in a tetsubin kettle instead.

Is a tetsubin the same as a teapot?

No. A tetsubin is a kettle with bare iron inside, used on heat. A cast iron teapot has an enamel lining and is used off the heat.

Where is Nambu tekki made?

In Iwate Prefecture, mainly Morioka and Mizusawa in Oshu City.

Can tetsubin go on an induction stove?

Only pieces labeled IH対応 (induction compatible). Most traditional kettles are made for gas or charcoal.

What does arare mean?

The raised hailstone-dot pattern found on many Nambu kettles and teapots.

References

1. 南部鉄器 (Wikipedia, Japanese). https://ja.wikipedia.org/wiki/%E5%8D%97%E9%83%A8%E9%89%84%E5%99%A8
2. Tetsubin (Wikipedia). https://en.wikipedia.org/wiki/Tetsubin
3. Kyūsu (Wikipedia). https://en.wikipedia.org/wiki/Ky%C5%ABsu
4. Nippon.com, Iwachū: Colorful Nanbu Ironware. https://www.nippon.com/en/guide-to-japan/gu900172/
5. Unagi no Nedoko, Oigen Foundry maker profile. https://unagino-nedoko.net/maker/2804/
6. CREA, Oigen Foundry in Mizusawa. https://crea.bunshun.jp/articles/-/34178
7. cotogoto, Visiting the Kamasada workshop. https://www.cotogoto.jp/blog/2018/10/kobo_kamasada.html
8. Yamagatagoto, Kikuchi Hojudo ceases business. https://yamagatagoto.com/kikuchi-hojudo/2257/