Koyanagi wide 150 mm (5.9 in)

Type: Ko-yanagi / Paring knife / Petty knife
Brand: Ishizuchi
Blacksmith: Buho Murata
Construction: Blue(Aogami) #1 high carbon steel with carbon steel cladding
Method: Hammer Forged
Blade Length: 150mm (5.9inch)
Blade Hight: 32mm(1.2in)
Weight: about 78g(2.7oz)
Spine Thickness: 2mm/at heel
Blade Type: Double-bevel
Core Edge Steel: Blue (Aogami) #1 High Carbon Steel
HRC (Rockwell Hardness): 62-63
Finishing: Black Finish (Kurouchi)
Handle: Walnut (Kurumi) with Plastic Ferrule
Place of Origin: Tosa, Japan

Detailed Description
Paring knives are small knives designed to preform small tasks such as peeling or carving fruits and vegetables. Paring knives are often used in the hand and off of the cutting board. Paring knives can range from about 3 inches on up to about 5 inches. Paring knives vary somewhat in profile since users vary in both their technique and the products they commonly use in cooking. Paring knives have a lot of crossover in use and design with utility knives and Japanese petty knives. Anyone looking for a paring knife should consider whether one of these other knife types may also fit their needs.

Blue Steel No.1 (Hitachi Metals Ltd.) is very similar to Blue Steel No.2, but the additional Carbon and Tungsten / Wolfram result in even better edge retention and toughness. The steel is perhaps most commonly seen in high-grade Japanese traditional single-bevel edged knives.

Black-finish is a state in which the surface that has been blackened by quenching is sharpened only with the blade, leaving the black side unintentionally on the sides ( Mine & Hira ) other than the blade.
There is no elegance like polished finish, but it has a taste of bumps and ruggedness. It also has the advantage of less rust than polished finish.