This book goes into the details of the making of a Japanese sword.
I own Sato's "The Japanese Sword : A Comprehensive Guide" as well as Yumoto's "Samurai Sword a Handbook", and they are clearly not as complete as that one (esp. Sato's.)
"The Craft of the Japanese Sword" is amazing in that it has a large number of extremely clear B&W pictures. Those are clear enough to show examples of the steel's grain, of what an utsuri looks like, of what makes nie different from nioi, of the appearance of the hamon at each stage of the polishing, etc. The clarity & quantity of the pictures is the main asset of this book to the katana enthusiast, be they interested in modern or antique swords, made in Japan or not.
The book is also great because of the info it provides on all the stages before the blade is forged (i.e., how to obtain the necessary steel ingot, or tamahagane) and after it is forged (polishing, of course, but also the craft of the scabbard, of the fittings, etc...)
This is a super dense book, packed with info, where not a single line is wasted. I cannot recommend it enough to anyone interested in the Japanese swords, be they swordsmiths, martial artists, or collectors. The book is geared toward the swordsmiths but provide so much info that a martial artist or collector planning to invest into a fine blade should absolutely read that book. This will prevent many a disappointment...