What size steel for a kiritsuke?

A kiritsuke is a long Japanese kitchen knife with a tall, mostly flat blade and an angled point. The preset is a 9 1/2 in blade (about 240 mm), 1.85 in tall at the heel, with a 1/8 in (0.125 in, 3.2 mm) spine and a 4 3/4 in hidden tang for a wa handle. Add 1/8 in for clean-up and you need 1.975 in, which rounds up to 2 in. That makes it 2 × 1/8 in flat bar, forged or ground. It is a close fit. A kiritsuke up to 1 7/8 in tall still fits 2 in bar. Any taller and the calculator moves you up to 2 1/2 in.

The matching KraftyDesign blank (the "Draw this blank" link) is long, and most of its edge runs flat. Near the front, the spine drops in a long straight line to a point close to the edge. Knife shops call that angled point a k-tip. The handle hangs from the spine line. KraftyDesign starts Japanese patterns at 3/32 in, but most of the shop knives below are thicker than that at the spine, so the preset uses 1/8 in.

The preset matches the double-bevel kiritsuke, often sold as a kiritsuke gyuto or k-tip gyuto. Four knife shops list five 240 mm kiritsuke gyutos at 44 to 54 mm (about 1.73 to 2.13 in) tall at the heel, so 1.85 in (47 mm) sits inside that range. Three of the five are over 1 7/8 in and would need 2 1/2 in bar. Four of the five measure 3 mm (0.118 in) at the spine above the heel, and 1/8 in matches them. The thinnest, at 2.24 mm (0.088 in), would come from 3/32 in bar.

A single-bevel kiritsuke runs thicker still. Two knife shops, Chef Knives To Go in Fitchburg, Wisconsin, and Knives and Stones, based in Sydney, Australia, list four 240 mm ones. They are 36 to 43 mm (about 1.42 to 1.69 in) tall and 3 to 5 mm (about 0.12 to 0.20 in) at the spine. None lands squarely on a stock size: the calculator puts the 4.8 and 5 mm ones on 2 × 1/4 in bar and the 3.5 mm one on 2 × 5/32 in, and a single bevel 1.54 in tall with a 3/16 in spine comes from 2 × 3/16 in. Back at the preset's 1/8 in, 52100, O1, AEB-L and 14C28N give the same 2 × 1/8 in bar as 1084, with no flags. 5160 gets two flags: 1/8 in is under the 0.156 in usually considered practical in it, and is not a thickness it is commonly listed in.

Stock removal, where the calculator starts, takes the whole 14 1/4 in profile plus clean-up: 14 1/2 in of bar per blade. That is about 16 oz of bar for a blade that finishes around 8 oz. A 12 in bar is too short (the calculator's minimum for this blank is 15 in). The 18 and 24 in bars give one blade each, 36 in gives two and 48 in gives three at the lowest cost per blade. Seven of the nine shop knives above weigh less than the 7.8 oz (221 g) steel-only estimate, even with handles, so it may run heavy. If yours comes out lighter, adjust the fill factors under Calibration.

Forged, the blade takes about 7 1/2 in of the same bar (about 8 1/2 oz) and finishes just under 6 oz, a 1.97:1 draw by the calculator's count. A 12 in bar gives one, 18 in two, 24 in three, 36 in four and 48 in six, with 24 and 48 in tied for the lowest cost per blade. To forge down from thicker stock, set "Forged thickness" to "One size up". That starts you at 2 × 5/32 in and about 6 in of bar, a 2.47:1 draw, just under the 2.5 the calculator flags. The calculator won't forge AEB-L, CPM-154, 14C28N, MagnaCut or A2. Pick any of them and it works out the bar as stock removal, even with Forged selected.

What a kiritsuke is for

A kiritsuke is a Japanese kitchen knife built to do two jobs. Korin, a Japanese knife shop in New York, calls it one of the few multipurpose traditional Japanese blades, usable as a yanagi (fish slicer) or an usuba (vegetable knife). Japanese Knife Imports, a knife shop in Beverly Hills, says kiritsukes are meant to combine the function of those two knives. Korin says the edge is straighter than a yanagi's for vegetables, and the blade is longer than an usuba's for slicing fish. Knifewear, a Canadian knife shop, gives 240 to 270 mm for traditional kiritsukes. It says you can slice sashimi with one, turn scallions into tiny ribbons and rotary peel a daikon radish. On The Kitchen Knife Fora, one poster who often uses a kiritsuke in a sushi restaurant lists negi (green onion) and katsuramuki (peeling daikon into one thin, continuous sheet) among its most common jobs, plus slicing fish and sometimes rolls. The same poster keeps it away from bones and tough sinew and calls it one of the most chip-prone knives they own. Another poster in that thread uses a 240 mostly on vegetables and rarely on proteins, and says kiritsukes take some practice to get comfortable with.

The traditional kiritsuke is single bevel. Knives and Stones says it is ground on one side with a concave ura on the other. The hollow is called the urasuki, and the deba page explains how makers grind it. Three of the four single-bevel shop knives above are listed as right-handed, and Japanese Knife Imports lists a left-handed 270 mm kiritsuke. All four have white (shirogami) or blue (aogami) steel at the edge, two steels the calculator doesn't carry. Three of the four are listed as clad in soft iron, the kasumi build the deba page describes, and the fourth has damascus cladding. Knifewear says single-bevel kiritsukes are quite uncommon these days, and that when most people say kiritsuke, they probably mean a gyuto (the Japanese chef's knife) with a cooler shape. It says these double-bevel knives became known as kiritsuke-tip gyutos, and that its shops started to see more of them around 2020 and 2021. Knives and Stones says the traditional knife is usually not as tall as a k-tip gyuto, but taller than a k-tip yanagiba and more of a vegetable knife. The Kitchen Knife Fora poster who uses a 240 says some single-bevel kiritsukes look taller than a gyuto, and favors ones that are not really tall, more like a yanagiba. Knifewear also says the kiritsuke has an especially delicate tip.

The stories in this paragraph come from shops and an uncited encyclopedia entry, and they disagree, so treat them as unconfirmed. Wikipedia describes the kiritsuke as a large hybrid with the length of a yanagiba and the height and profile of an usuba, with an angled tip as a compromise, and puts it at 24 to 30 cm. Korin says that traditionally only executive chefs used it, as a status symbol and because it is hard to use. Chef's Edge, a knife shop in Leederville, Western Australia, says many kitchens let only the head chef use one. Knifewear calls the head-chef story completely untrue. It says single-bevel knives do take more practice, but anyone is welcome to use them. Knifewear also says the single-bevel kiritsuke was first meant for slicing delicate terrines and the like. Chef's Edge dates the kiritsuke to before the Meiji era (before 1868), yet says in the same article that no one knows exactly how or when it was first used. That article also gives the usuba the job of slicing fish and the yanagiba the job of preparing vegetables, the reverse of what Korin says. The name is unsettled too. Japanese Chefs Knife (JCK), the online shop of a knife exporter in Seki, Japan, says kiritsuke (切付) literally means "to cut and attach" or "slit open", and Chef's Edge gives "slit open". Knifewear says the kiritsuke and the bunka share some DNA but have very different origins: it traces the bunka to makers putting a tip on the nakiri, and calls the single bevel a very old way of making kitchen knives.

Stock for a kiritsuke

In a BladeForums sale thread, one seller's 9 in AEB-L kiritsuke was 0.13 in thick at the spine with a full distal taper, and was taken down to .004 in at the edge before sharpening. Another seller's BladeForums listing puts a 240 mm O1 kiritsuke at 2 mm (5/64 in) thick at the heel and 50 mm (2 in) tall, which the calculator would put on 2 1/2 × 3/32 in bar.

Widths assume blade height + 1/8 in rounded up to stock; thickness is the finished spine rounded up. Change the inputs above for your own pattern.

Steels that suit it

Questions