The Japanese Hon-deba (in Japanese Hon means original or true), is traditionally used for filleting fish, but it is also commonly used for dressing poultry or even a vegetable cleaver. It is the thickest and heaviest of Japanese knives.
The weight of the Hon Deba is desirable because, with adequate care, the sturdy heel section of the knife can be used to cut or chop through the bones found in small and medium-sized fish and poultry.
The deba knife is single-ground so very sharp, able to pierce skin and scales and flat-backed to glide over rib bones. That extra weight is no longer an impediment to delicate work, it seems to actually steady the tip.
Single bevels knives have more acute angles on their edges that excel at cutting softer, thinner product like fish but in return require a different skill set to use and sharpen. There are some more Western Debas which are ground on both sides. These knives are designed to handle very heavy tasks like splitting chickens or gourds.
The Hon Deba knife looks, and in the beginning feels, like a heavy “chopper” style blade. It is thick at the spine and does not begin to narrow much until at least halfway down the blade. There is absolutely nothing in the design to minimize weight. Rather the heel end of the blade is used as a chopper when removing fish heads.
The chef takes a hammer like grip on the handle of this chefs knife and brings the very back end of the bade down hard on the bone - and normally goes through at a stroke.