Brian’s Guide to Japanese Chisels

Hello and welcome to my blog.  I regularly receive inquires requesting information about types, uses and recommendations for Japanese chisels.  I’ve put together this guide to provide a basic understanding of Japanese chisels and to help those who inquire.  I do teach individual classes on use and setup of Japanese tools, however I am not an authority on Japanese tools, so please consider this a layman’s guide.  Please remember; ‘Don’t Panic’.

Types and Uses

Oiire Nomi

Oiire nomi are the common bench chisel, these are for general use and something I find myself using very commonly.  A typical set of Oiire nomi will range from 3mm to 42mm, a larger set will typically include 1.5mm and 48mm.  The Oiire nomi I show here are shaped in a mentori profile (chamfered) but they are also very commonly made in a kaku-uchi profile (box shape).

Shinogi Nomi

Shinogi nomi are very commonly referred to as dovetail chisels and I use them to aide in ease of dovetailing, however it is my understanding that they’re not in fact made for that purpose.  Instead they’re made for cutting the sidewall of a mortise.

Ichou-gata Nomi

Ichou-gata nomi are fishtail chisels, they’re very commonly used to aide in half-blind dovetail cutting.

Mukoumachi-Nomi

Mukoumachi-nomi are mortise chisels, these chisels are the first tool used in cutting a rectangular mortise.  Unlike western chisels these are NOT made to be levered on.

Sokosarai Nomi & Kama Nomi

Sokosarai nomi are used to scrape the bottom of a blind mortise.  These chisels are essential kit for cutting mortises with Japanese chisels.

Kama Nomi are good for cutting inside corners

Fukamaru Nomi

Fukamaru chisel, or deep scoop gouges, are carving chisels.  These are made in a huge variety of sizes and are the most basic of carving chisels.  There many shapes produced for carving.

Tsuki Nomi

Tsuki-nomi are paring chisels, they come in three basic orientations, which are Tsuki (paring), Usu (thin paring) and Hon-tsuki which are very large timber paring chisels.

Kote Nomi

Kote nomi are cranked neck chisels made for paring grooves.

IMG_9391.jpg

Tataki Nomi

Tataki nomi are timber chisels, they are made very hefty and used for a basic timber framing work.  The chisels shown here are chu-tataki they are a smaller version of those timber chisels, but larger than oiire-nomi.  These chisels are made for light timber work.

 

Shapes

The basic chisel shapes, which refers to the shape of the chisel sides are Mentori (chamfered), Shinogi (triangle shape) and Kaku-uchi (box shape).  These are shown left to right.

Finish Types

Japanese chisels come in a few basic finishes to the blade, the most common is a lacquered black finish with a ground ura or hollow.  This is a basic type that mimics a more ideal type of finish; simple forge black finish.

Forge black finish shows the skill and quality of the tool very well.  The tool must be properly finished (filed) and ura correctly made prior to heat treating in order to achieve a clean forge black and Kuro-ura (black ura).

Some makers perform a very special finish on the ura (back side) of the blade.  The process is done by scraping with a sen (scraper tool).  This is an indicator of a high skill level in finishing chisels or any tool and is usually reserved for very fine tools.  Some makers will leave the forge black on this, others may choose to show it off.

Finally, there is a polishing finish.  Polishing finish is one in which the maker applies a fine file finish after heat treating.  This finish is lacquered clear to retain the appearance, this is also indicative of a high skill level but it is considered very flashy.

Forge black & Kuro-Ura

IMG_9388

Forge Black and Sen Scraped Ura

IMG_9390

Polishing Finish

IMG_9376

Basic Parts:

Japanese chisels are constructed of a forge welded blade.  The blade is composed of a layer of hard steel, hagane, welded to soft iron or jigane.  This structure forms the cutting edge and it’s support.  This is the reason why Japanese chisels can be made with such hard steel edges.

Japanese chisels are tang chisels with a ferrule used to center and support the handle.  The butt end of the handle is captured in a hoop.  The hoop keeps the handle from splitting or deforming under pressure from repeated hammer blows.

Japanese chisels with a hoop are intended to be struck with a steel hammer, known as a genno.  This hammer is specifically constructed for this use.

Recommended Makers

I recommend a handful of makers, I’ve used and currently use these makers but please DO NOT consider this to be the final list on whose who in chisel making.  There are many incredibly talented blacksmiths and I have not used them all, not even close.  So consider this only the list of makers I’ve myself used and enjoy.  I’m not being paid to recommend these chisels.

Kikuhiromaru – White 1, found on www.Japan-Tool.com/zc

Stan Covington’s brand – White 1 chisels

Konobu – Assab K120 (old stock steel, new make chisels) found on www.Japan-tool.com/zc

Kunikei – White 1 – Found on www.Japan-tool.com/zc

Steels

Japanese chisels, of the forged variety, are typically made in a handful of steels.   Steels can be a near endless debate, but I prefer simple high carbon steels.  Ironically these simple steels are best handled by talented makers capable of working them to the degree required in order to have a strong, sharp, hard and yet durable tool.

I mainly prefer to use Hitachi White Paper 1 steel, Assab K120 (old stock 1.2% carbon) steel, and occasionally Hitachi Blue 2 steel.  I avoid the exotic steels as they’re increasingly difficult to sharpen on fine natural stones, which create the finish I prefer for my cutting edges.

Handle Materials

Japanese chisels are offered in a variety of handle materials, my preference leans toward the more basic types of materials.  I find Japanese white oak, boxwood and Gumi to be durable enough to survive heavy use and yet forgiving enough that they provide a dead-blow effect to the cut.  If possible, I prefer to use a handle cut from branch stock which retains the pith in the center of the handle.

If you would like to learn more, please consider taking a class.

Handtool Setup and Use

Japanese Chisel Setup – Kazura

Goumi Handle Making

 

The chisels in this post are made by Konobu, Kikuhiromaru, Kunikei, Stan Covington’s Maker and Tasai.

Sharpening Stone Selection

Guide to Japanese Whetstones
Japanese Natural Stones: A User’s Perspective