Kitchen knife hardness comparison

[grepper]

A couple of question for everybody: Does anyone have a kitchen kife with SG2 or ZDP-189 (MC66) steel, Rockwell 62 or greater?  Probably Zwilling or Shun.  If so, what do  you think about it?  Does it maintain its edge significantly better?  Do you have a problem with chipping?

I noticed that my kitchen knives dull pretty quickly.  When freshly sharpened they hang on the back of a thumbnail and are very sharp.  But, even after just one session of vegetable chopping, the edge loses its super sharpness, and won't hang on a thumbnail etc.  Still sharp, not just super sharp.

I love to sharpen, but I find this tiresome, so I started looking into the comparative hardness of different brands of kitchen knives.  It quickly became obvious why most of my knives perform similarly.

This research took a surprisingly long time and I find it tedious.  I tried to glean information from the manufacturer's web site as often as possible.  When I could not find the information there, I tried to use as reputable a source as possible such as Sur La Table etc.

Obviously  this is a very incomplete list, but you soon get the idea.  Most knives are Rockwell (HRC) 55-60.  A few are above 60, fewer are 62 and one that I found was 66.  A 6" Zwilling Twin Cermax Utility knife is currently available at Bed Bath and Beyond and Amazon, etc., for about $160.  I'm tempted. I love its edge profile and handle shape.  So, hence my questions I asked earlier.

BTW, I struggled to get the following to format correctly.  Frustrating.  I give up.  It's close enough to be useable.

Enjoy!

Manufacturer                           HRC          Steel
Zwilling:      
Bob Kramer - Euro Carbon          61    Carbon 52100
Bob Kramer - Euro Stainless       63     Blade core SG2 powder steel, embedded in 100 layers of steel of two varying grades of hardness.
Zwilling Damascus                       61       160 layers
Twin 1731                                   60      Cronidur 30 - Stainless
Zwilling Cronidur                         60       Cronidur 30 - Stainless
Zwilling Profection                       60        Rust resistant
Zwilling Pro                                 57       High-carbon, rust-resistant stainless steel
Twin Cermax                               66       ZDP-189 (MC66)
Twin Cuisine                               57        High carbon - Stainless
Twin Four Star                            57       High carbon - Stainless
Twin Four Star II                         57       High carbon - Stainless
Twin Select                                 57       High carbon - Stainless
Twin Five Star                             57       High carbon - Stainless
Forged Synergy                          57       Stainless
Classic                                        63       SG2

Shun:      
SG2 knives                                 61-62   SG2 Stainless
VG-10 knives                             60-61   VG-10 Steel knives

Calphalon                                  54-56   High carbon - Stainless

Global                                         56-58     Molybdenum/Vanadium stainless steel

Kasumi                                        60           VG10

MAC                                           58 or 60     Stain resistant

Messermeister Japanese                57-58       Stainless

Mora Cook's Knife 4216PG        58-60            Possibly Sandvik 12C27, Mora uses Snadvik, high carbon or laminated.  All HRC 58-60

Nenox                                       60    Nenox - Rust resistant

Rachel Ray (Furi knives)            56        Stainless

Tojiro:
DP                                             60-61    VG-10
Pro Nickel Damascus                    63        VG-10

Wusthof                                    58       X50 Cr MoV 15

[Ken S]

Grepper,

What kind of cutting board are you using? I use wood, which is more forgiving on the knife edges.

Ken

[grepper]

Hi Ken,

I use a nice, thick slab of stainless steel as it's sanitary and easy to clean.

Just kidding. Wood or thermoplastic.

I'm sure a SG2 or ZDP-189 HRC 62+ would be very nice.  Really sharp, hard steel.  They are just a little pricey.

I have a Wusthof that seems to do better than some others, but still it's only HRC 58.  HRC 62+ is would be much harder!

Mark

[Stickan]

Nice list! You could ad Sandvik steel 12C27, stainless with very longlasting edge. Used by many Scandinavian knive companies (Frost, Mora of Sweden, EKA etc.)

I´m a knife nut too and have some nice chef knives and we have rules att our home how to treat the more expensive knives 

Never in the dishwasher, always handwash, dry them and hang them on a magnet holder.
If you have a woodblock to have your knives in, put the knives in on their backside.
Always use the backside when removing meat/sallad and such from the cuttingboard.

This easy things makes my japanese knives sharp for a long time and i sharpen them about once a year, but I use the honing wheel about 2-3 times a year.

And each steel has various reaction on the edge you will give them.
I dont need to (or my wife, she is the chef in the house) have the knifes under 20 degrees. Mine are mainly about 20-30 degrees, fine for sallad and meat.

[grepper]

Thanks Stickan,

I add the Mora Cook's Knife 4216PG.  They don't specify exactly the steel used, but their website says that they use Sandvik, or high carbon or laminated steel, all HRC 58-60.

Cook's Knife 4216PG

Blade: Blade made of Swedish cold-rolled stainless steel. Hardened by deep refrigeration at -80 degrees for maximum hardness. Hardness: 58 RC.
I really like that type of blade profile.  A lot to chef's knives are too pointy for me.
http://www.moraofsweden.se/fish/cooks-knife-4216pg

Do you happen to have any really hard steel HRC 62/62+ clanking and bouncing around with the other knives in your drawer?  I'm really curious how they perform.

[somecallmetim]

I own a 10" Shun Elite Chef Knife, made with SG-2. The steel is EXTREMELY hard, so hard that when I took it to the Kershaw HQ to get it sharpened they made dozens of tiny chips on the edge! Even the company that makes the knife doesn't know how to sharpen it.

I have the Tormek T-7 with the SJ-250 Japanese waterstone and have had great results with other knives. I have yet to attempt sharpening the SG2 knife, honestly kind of afraid to... I will try sharpening it soon.

[Herman Trivilino]

I own a 10" Shun Elite Chef Knife, made with SG-2. The steel is EXTREMELY hard, so hard that when I took it to the Kershaw HQ to get it sharpened they made dozens of tiny chips on the edge! Even the company that makes the knife doesn't know how to sharpen it.

I'm a little confused here.  Is Kershaw the company that made it?  That knife has a lifetime warranty, so you should be able to have it replaced.

I have the Tormek T-7 with the SJ-250 Japanese waterstone and have had great results with other knives. I have yet to attempt sharpening the SG2 knife, honestly kind of afraid to... I will try sharpening it soon.

The only time I've seen the edge chip was on these cheap pocket knives from Pakistan.  I had to sharpen them at a very blunt angle to keep them from chipping. 

I understand that this is not the case with your expensive knife.  It seems that the SJ is too smooth to be able to remove enough steel to remove the chips.  I would try the SG dressed with the fine side of the stone grader.

[grepper]

Somecallmetim, thanks for letting us know about your experience with your Shun.

FWIW:
From: http://en.wikipedia.org/wiki/Kershaw_Knives
"In 1977, Kershaw became a wholly owned subsidiary of the KAI Group...  Kai USA Ltd. has three lines of products; Kershaw Knives brand of sporting and pocketknives, Shun Cutlery, handcrafted Japanese kitchen cutlery, [4] and Zero Tolerance, a line of premium and professional knives."

From: http://shun.kaiusaltd.com/warranty
"Yes! Effective September 4, 2012, Kai USA Ltd. is once again sharpening your Shun cutlery for free, for as long as you own it. It's as simple as that."

The steel is EXTREMELY hard, so hard that when I took it to the Kershaw HQ to get it sharpened they made dozens of tiny chips on the edge!

Something is wrong there.  Either Kershaw screwed up sharpening it, or there is a problem with the steel of your knife.  Like Herman mentioned, your knife has a lifetime warranty.  Considering that is a very fine and expensive knife, I'd take them up on it and get it sharpened properly or replaced.

Shun discusses chipping in their FAQ: http://shun.kaiusaltd.com/faq See the section, "Why are there so many reviews complaining of chipped blades?"

Don't be afraid!  Just sharpen it!  Why not?  You can always send it in and get it sharpened for free.  Anyway, please let us know when you give it a try.

Sadly, I've never had the opportunity to sharpen a Shun or other SG2 or really hard steel knife.  I'd love to try!  I thought I'd just pick up a 3.5" Shun paring knife to play with, but they are $170.00 US!  It would be a great little knife to have, but a little on the pricy side when my main reason to purchase one would be to make it dull just so that I could sharpen it. 

[Herman Trivilino]

Shun discusses chipping in their FAQ: http://shun.kaiusaltd.com/faq See the section, "Why are there so many reviews complaining of chipped blades?"

Quote from that FAQ: 

     "What's more, micro chips can easily be sharpened out. Our Warranty Service Department will be happy to help you with that.

       Of course, if there is a problem with the materials or manufacturing itself, we'll take care of that, too. Just send in your knife to our
       Warranty Service Department for evaluation."

It seems as if whoever tried to sharpen that knife really screwed up.

[michael clark]

I have vintage knife collection,, its good.. some of your knife was really awesome...