HAP40 is a powdered high-speed semi-stainless steel from Hitachi Metals - and it has earned a devoted following among serious cooks for one reason above all others: edge retention that is simply in a different category from anything else. Kitchen knives made from HAP40 hold their edge three to five times longer than traditional carbon or stainless steels. At 65-66 HRC it is harder than Aogami Super, harder than SG2, and fine-grained enough to take a screaming sharp edge and give it back easily on quality water stones. CKTG has been calling it Voodoo Steel for years - and anyone who has used it understands why.
The gyuto at 270mm features a thin distal taper toward the point and a profile that is fairly flat all the way to the slim tip - nimble and precise despite the blade length. The thin grind lets the blade pass through food with minimal resistance, and the 60/40 asymmetric edge - biased right with a feathered tip - works equally well for right- and left-handed cooks. Stainless san-mai cladding over the HAP40 core keeps daily maintenance straightforward. Upgraded dark grey pakka wood handle. Profile is fairly flat to a slim tip - nimble for a 270mm. Height 52.4mm. CKTG is the only source for the Kohetsu HAP40 line.
What Customers Are Saying: Reviewers describe an insane edge retention that starts losing peak sharpness only after sustained pro use - one sushi bar cook bought the 210mm specifically because the 270mm was too good to give up. The laser-like thinness and upgraded pakka handle are called out as defining characteristics of this version.
Care Instructions: HAP40 is a semi-stainless steel - the stainless cladding fully protects the flanks and the HAP40 core has meaningful corrosion resistance, but hand washing and drying after each use is still best practice. Avoid the dishwasher. HAP40 at 65-66 HRC is harder than most kitchen steels - use wood or rubber cutting boards only and avoid bones, frozen foods, and hard materials that could chip the edge. Sharpen on quality water stones; HAP40 sharpens more easily than most powdered steels but rewards patience and consistent angle. Strop regularly between sharpenings to maintain peak performance.
The gyuto at 270mm features a thin distal taper toward the point and a profile that is fairly flat all the way to the slim tip - nimble and precise despite the blade length. The thin grind lets the blade pass through food with minimal resistance, and the 60/40 asymmetric edge - biased right with a feathered tip - works equally well for right- and left-handed cooks. Stainless san-mai cladding over the HAP40 core keeps daily maintenance straightforward. Upgraded dark grey pakka wood handle. Profile is fairly flat to a slim tip - nimble for a 270mm. Height 52.4mm. CKTG is the only source for the Kohetsu HAP40 line.
What Customers Are Saying: Reviewers describe an insane edge retention that starts losing peak sharpness only after sustained pro use - one sushi bar cook bought the 210mm specifically because the 270mm was too good to give up. The laser-like thinness and upgraded pakka handle are called out as defining characteristics of this version.
Care Instructions: HAP40 is a semi-stainless steel - the stainless cladding fully protects the flanks and the HAP40 core has meaningful corrosion resistance, but hand washing and drying after each use is still best practice. Avoid the dishwasher. HAP40 at 65-66 HRC is harder than most kitchen steels - use wood or rubber cutting boards only and avoid bones, frozen foods, and hard materials that could chip the edge. Sharpen on quality water stones; HAP40 sharpens more easily than most powdered steels but rewards patience and consistent angle. Strop regularly between sharpenings to maintain peak performance.
- Brand: Kohetsu
- Exclusive: CKTG Exclusive - Available Only at CKTG
- Blacksmith: Tsukahara Family
- Location: Seki City, Japan
- Construction: Laser Cut, San Mai
- Edge Steel: HAP40 Semi Stainless (Powdered High Speed Steel)
- Cladding: Stainless Steel
- HRC: 65-66
- Edge Grind: 60/40 Asymmetric Double Bevel
- Engraving: Acid Etched Kanji
- Handle: Octagonal Dark Grey Pakka Wood
- Blade Length: 270mm
e performance for greens like heads of lettuce, bundles of h
7 review(s) WRITE A REVIEW (Reviews are subject to approval) It's good, December 25, 2025 What a blades Incredible edge retention Worth the wait Very light - ultra fast gyuto Great knife Razor Sharp Blade with Excellent Balance
7 review(s) WRITE A REVIEW (Reviews are subject to approval) It's good, December 25, 2025Posted By: Ed
Bought this knife to compliment a hap40 210mm gyuto that has insane retention(started losing peak sharpness after a few months) so when I saw this on cktg I had to go for it. Beautiful knife but was not satisfied with the factory edge. If purchasing get your sharpening system ready or go with the cktg sharpening. Look forward to it's performance in the coming months.
Bought this knife to compliment a hap40 210mm gyuto that has insane retention(started losing peak sharpness after a few months) so when I saw this on cktg I had to go for it. Beautiful knife but was not satisfied with the factory edge. If purchasing get your sharpening system ready or go with the cktg sharpening. Look forward to it's performance in the coming months.
What a bladesPosted By: Eric Hollis
34 people found this review helpful
Truly amazed with this 270 HAP 40, thin and razor sharp! Light and nimble but robust and strong. No other metal has this feel and I’ve got most of the others. Time to cash in on the old knives and get all HAP! Order with confidence!
34 people found this review helpful
Truly amazed with this 270 HAP 40, thin and razor sharp! Light and nimble but robust and strong. No other metal has this feel and I’ve got most of the others. Time to cash in on the old knives and get all HAP! Order with confidence!
Incredible edge retention Posted By: Jesse
31 people found this review helpful
Was a little disappointed when I first received my knife due to a chip at the heel of the blade and the edge seemed like more extreme than 60/40 and more like 70/30. Definitely wasn't ready to go out of the box although I did attempt to use it for about a week before fixing the issues and it performed ok. Chefknivestogo.com is a great business and compensated for the chipped blade, I've bought most of my chef knives through them and they're always a pleasure to do business with.
It is fairly easy to sharpen, takes a little longer than my R2 steel knives but not much, and the edge lasts at least twice as long as the r2 steel so it's well worth the extra time it takes to sharpen.
Best knife in my bag. I highly recommend this knife.
31 people found this review helpful
Was a little disappointed when I first received my knife due to a chip at the heel of the blade and the edge seemed like more extreme than 60/40 and more like 70/30. Definitely wasn't ready to go out of the box although I did attempt to use it for about a week before fixing the issues and it performed ok. Chefknivestogo.com is a great business and compensated for the chipped blade, I've bought most of my chef knives through them and they're always a pleasure to do business with.
It is fairly easy to sharpen, takes a little longer than my R2 steel knives but not much, and the edge lasts at least twice as long as the r2 steel so it's well worth the extra time it takes to sharpen.
Best knife in my bag. I highly recommend this knife.
Worth the waitPosted By: Christian
32 people found this review helpful
I had my eye on this knife for months. I was delighted when it finally came in stock. It was even more esthetic when I got to use it for the first time at work. Out of the box that came with a very nice edge. It was able to take hair of my arm.
It performed amazingly well in the first few hour. Sadly on its first day a coworker chipped the blade in about 8 spots. It took two hours to fully repair and bring up to an 8K edge. Its edge has stayed very keen especially considering it regularly travels with me to work.
The performance for greens like heads of lettuce, bundles of herbs, and large peppers has been a delight. The balance point is either at my pinch grip or slightly towards the tip depending on if I slightly adjust my grip. The handle is Definitely my favorite part. Its uniform construction with not ferrule bump is a dream and its easy to clean. The pakka wood also has not absorbed any smells after pounds of onions like other woods have in the past.
Over all I am still in love after these months!
32 people found this review helpful
I had my eye on this knife for months. I was delighted when it finally came in stock. It was even more esthetic when I got to use it for the first time at work. Out of the box that came with a very nice edge. It was able to take hair of my arm.
It performed amazingly well in the first few hour. Sadly on its first day a coworker chipped the blade in about 8 spots. It took two hours to fully repair and bring up to an 8K edge. Its edge has stayed very keen especially considering it regularly travels with me to work.
The performance for greens like heads of lettuce, bundles of herbs, and large peppers has been a delight. The balance point is either at my pinch grip or slightly towards the tip depending on if I slightly adjust my grip. The handle is Definitely my favorite part. Its uniform construction with not ferrule bump is a dream and its easy to clean. The pakka wood also has not absorbed any smells after pounds of onions like other woods have in the past.
Over all I am still in love after these months!
Very light - ultra fast gyutoPosted By: George - verified customer
6 people found this review helpful
I have purchased this gyuto for I wanted to try out something exotic, in terms of steel. I already had a ZDP-189 gyuto so I have decided to buy another Hitachi PM steel - the HAP40.This knife is 270mm but still my lightest gyuto. I love this one for it is very thin - goes through everything, and never tires your lower arm muscles - even after hours of chopping.Edge retention is a lot better than what I got used to with my ZDP-189 and still feels just as sharp.I put a 8k edge onto this one - around 35 deg total edge - and there is no chippig.I would highly recommend this gyuto to anyone who wish to see a very hard steel knife but just hate the idea of all time chippings, what is present on other 65+ HRC steels. This one is an exception - in one week became my everyday workhorse.PROS: takes a very very keen edgevery light very precisevery thinmoderately high at heelvery nice and flawless fit & finishCONS: a tiny - I mean almost undetectable geometry problem - around 1/3rd from the heel there is a edge curvature problem - the knife bumps a little. Took me around 20 mins to fix - no big deal.Overall rating: 95%I wish all my knives would be just like this....
6 people found this review helpful
I have purchased this gyuto for I wanted to try out something exotic, in terms of steel. I already had a ZDP-189 gyuto so I have decided to buy another Hitachi PM steel - the HAP40.This knife is 270mm but still my lightest gyuto. I love this one for it is very thin - goes through everything, and never tires your lower arm muscles - even after hours of chopping.Edge retention is a lot better than what I got used to with my ZDP-189 and still feels just as sharp.I put a 8k edge onto this one - around 35 deg total edge - and there is no chippig.I would highly recommend this gyuto to anyone who wish to see a very hard steel knife but just hate the idea of all time chippings, what is present on other 65+ HRC steels. This one is an exception - in one week became my everyday workhorse.PROS: takes a very very keen edgevery light very precisevery thinmoderately high at heelvery nice and flawless fit & finishCONS: a tiny - I mean almost undetectable geometry problem - around 1/3rd from the heel there is a edge curvature problem - the knife bumps a little. Took me around 20 mins to fix - no big deal.Overall rating: 95%I wish all my knives would be just like this....
Great knifePosted By: Mike - verified customer
5 people found this review helpful
Like all my knives from cktg, it's awesome. This knife holds an edge, and is gorgeous. I have a set of masakage koishi knives among others. And I got this knife 270mm for when I'm cutting large quantities and it goes through everything quick and easy. A definite great buy!!!
5 people found this review helpful
Like all my knives from cktg, it's awesome. This knife holds an edge, and is gorgeous. I have a set of masakage koishi knives among others. And I got this knife 270mm for when I'm cutting large quantities and it goes through everything quick and easy. A definite great buy!!!
Razor Sharp Blade with Excellent BalancePosted By: Mike - verified customer
9 people found this review helpful
I have been using the knife for a week and am floored by its abilities. Knife came with a sharp edge (as others mentioned not razor sharp out of box but quite sufficent) and seems to hold the edge through a lot of tough work. Also, I feel I should mention that this does not feel like a normal 10.5 inch chefs knife as it is lighter than any of my 8 inch European chefs knives. My girlfriend was daunted by its size, but was incredibly surprised by the nimbleness of the knife once she started using it. I was debating between the 240 mm and the 270 mm and have no regrets with the 270, it is a great size! Personally I am utilizing this as a home cook, but as an ex-cook I would have loved to have this beast during long prep sessions and on the line.
9 people found this review helpful
I have been using the knife for a week and am floored by its abilities. Knife came with a sharp edge (as others mentioned not razor sharp out of box but quite sufficent) and seems to hold the edge through a lot of tough work. Also, I feel I should mention that this does not feel like a normal 10.5 inch chefs knife as it is lighter than any of my 8 inch European chefs knives. My girlfriend was daunted by its size, but was incredibly surprised by the nimbleness of the knife once she started using it. I was debating between the 240 mm and the 270 mm and have no regrets with the 270, it is a great size! Personally I am utilizing this as a home cook, but as an ex-cook I would have loved to have this beast during long prep sessions and on the line.
