Tojiro Zen Black Petty Knife

The petty or utility knife is a small, multipurpose blade that offers the versatility of a chef’s knife in a smaller package. Developed in Japan in the late 19^th century with influence from European patterns, this knife is suited for most smaller items or for any task that requires a nimble blade. It can be paired with a gyuto (chef’s knife) to cover the majority of your needs in the kitchen.

Function

The petty knife is similar in form to a large paring knife, making it useful for paring fruits and vegetables. The gently curved blade, much like the chef’s knife, is also useful for slicing meat and for chopping small produce.

Form

The blade is made using the centuries-old san mai (“three-layer”) construction technique, in which a hardened steel core is forge welded to a jacket of softer steel for strength. Tojiro Zen and Zen Black blades are forged with a core of VG-10 cobalt alloy steel, a high-carbon stainless steel developed in Japan. Hardened to a Rockwell hardness of 60, it accommodates a long-lasting, razor-sharp edge. The core is clad in 13 chrome stainless steel, which strengthens the blade and guards against corrosion.

Zen Black blades are additionally treated with a black oxide conversion finish, which anodizes a microscopic layer of metal on the surface to chemically stable magnetite (Fe₃O₄). Often used on medical implements, this treatment improves the steel’s resistance to saltwater and is popular on boats or in coastal areas.

The handle is crafted from lightweight chestnut wood, which provides a secure grip without upsetting the knife’s balance. The wood is fire-blackened, enhancing its durability and water resistance, and secured with a ferrule (collar) of polypropylene resin. Its D-shaped shinogi profile maximizes comfort and ease of control.