BG-42 or CPM S30V in the kitchen?

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Sid Post

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Okay, I tried the search feature but, it is not working for me.

I am looking at comissioning a custom kitchen knife. BG-42 or CPM S30V? Why? THANKS!
 
They are very similar ,both excellent steels but S30V will be easier to sharpen .
 
For a western style knife, neither one, 420HC would be a much more suitable choice, greater toughness and durability and corrosion resistance, with cryo you can get it 55 HRC. The higher wear resistance of BG-42 and S30V would be of little benefit and the higher hardness would not be sigificant either as blunting in the kitchen is generally limited by accidental contacts for such rougher use knives.

For a Japanese style knife, you are looking at much more precision cutting and thus you don't need high levels of toughness nor ductility, and corrosion resistance as well isn't that great a deal as that kind of mindset is one which tends to have the blades rinsed and dried frequently anyway and thus such knives are frequently made of carbon steel. I would go with BG-42 as it can be made harder than S30V, but would go with S90V if you wanted to be extreme, get it ~63 HRC.

-Cliff
 
Cliff i agree with the S30 V . im actually starting "Kitchen " knives out of it at the start of the year .

Should be interesting .

Matt
 
To clarify, it is not that I think S30V would be a bad choice, the problem is compare it to 402HC with a quality heat treatment in terms of both performance and price, if I had money to burn, then yes I probably would go for it for the Japanese style knife (very fine and acute edge), but for that style of use (very light cutting) where sharpening is trivial as you are indoors next to a set of crock sticks or smooth steel, and the rate of blunting is very low anyway, there isn't a real incentive to go beyond 420HC.

Now however when you start looking at utility knives then edge retention can be a lot more demanding and wear resistance can be a large factor. You are also not as comfortable in sharpening as you are frequently out and around and may be doing some tasks which could blunt a 420HC blade so badly that you might need to stop and sharpen which you might want to avoid for obvious reasons.

-Cliff
 
So do you think S30V is bad or inapropriate for Kitchen?

ive thought about 154 CM , or 440 with a proper heat treat and cryo.
 
Cliff, I think most blunting of knives in the kitchen occurs from cutting food with the wrong type of surface underneath the food -- ceramic plate, metal roasting or baking pan, acrylic or glass cutting boards, etc.

Bruce
 
Im with Bruce on cutting surface dulling. I use 420hc, Ats 34, bg42, and S30V in the kitchen and the same rule applies as with hunting: Clean the knife after use. I wash my knives separate for safety.
 
Originally posted by Cliff Stamp
For a western style knife, neither one, 420HC would be a much more suitable choice, greater toughness and durability and corrosion resistance, with cryo you can get it 55 HRC. The higher wear resistance of BG-42 and S30V would be of little benefit and the higher hardness would not be sigificant either as blunting in the kitchen is generally limited by accidental contacts for such rougher use knives.
Click to expand...

Looking at a custom kitchen knife, where would I go to find a 420HC blade steel knife with the right heat treat? Is the cost savings referenced really significant? Raw materials for the most part do not significantly affect the price (assuming nothing exotic or rare materials wise) when compared to the labor required to make the knife itself. I don't have money to burn but, want something better then a Forschner or Wustoff. Where else should I be looking?

Originally posted by Cliff Stamp
For a Japanese style knife, you are looking at much more precision cutting and thus you don't need high levels of toughness nor ductility, and corrosion resistance as well isn't that great a deal as that kind of mindset is one which tends to have the blades rinsed and dried frequently anyway and thus such knives are frequently made of carbon steel. I would go with BG-42 as it can be made harder than S30V, but would go with S90V if you wanted to be extreme, get it ~63 HRC.

-Cliff
Click to expand...

I do not see many knives made in S90V these days and, I do not find many knifemakers who offer it as an option either. How much difference would I see in the kitchen between a high RC BG-42 blade or S30V for S90V? Again, anyone have knifemaker references that make custom kitchen knives out of these materials that can "fine tune" the heat treat for this specialized application?

Thanks!
 
Bruce, yes that is what I meant by accidental contacts. I have run edge retention trials where I used the cheapest knife I could find in the kitchen ($5 no name mystery stainless), and after a few weeks and no significant loss of edge retention I concluded that the demands on a steel which cutting food are not significant. It is the accidents that cause blunting, or poor choice of cutting boards as you mentioned. It takes a long time for meat or potatoes to blunt steel.

Pinoy, I would not say bad, just overkill. There is a misconception that steels can be "good" or "bad" or have good "edge retention" or whatever, as some kind of general law which this is quite frankly nonsense. For example take 1095 and harden it to 66 HRC and use it on cardboard and general light work, you find that the edge retention is excellent and sharpening is easy. Take the same steel and hardness and use it on a heavy chopper and the edge retention is horrible and sharpening poor as the steel chips too readily.

Look at what S30V offers over ATS-34 class steels, it has no significant gains in toughness, ductility, or hardness. It does have better wear resistance, but as noted in the above this has little to no effect in any kind of kitchen use. AISI-420 HC at 55 HRC has excellent toughness and ductility and corrosion resistance and thus makes a wonderful western kitchen knife for those people who do on occasion mash the knife into a metal pot or whack it into a bone. You can still put a very fine edge on the knife and have a roll or dent rather than a chip.

Now if you want to make a more fine use knife then you move up to a harder stainless. Since these knives are used very carefully you don't need sigificant toughness which is why the japanese blades can be up to 65 HRC. Now ATS-34 class steels have an advatange over AISI-420HRC as they are ~5-7 HRC points harder and thus you will see less edge roll and thus a greater edge life. However quite frankly, I would see this as more of a status symbol than any real functional advantage because kitchen knives blunt *so* ver slowly when used carefully anyway. This only real reason I would seek out a harder knife is if I was doing a lot of cutting of shellfish, or working around a lot of bones (not chopping), otherwise you are gaining nothing significant.

Sid, Phil Wilson makes kithchen knives in AISI-420HC (this steel he most often recommends) but will make them out of S90V very hard if you want.

-Cliff
 
Cliff, I guess I wouldn't have called knife contact with a surface supporting the food an "accident". Almost nobody tries to "pull" their cutting or slicing motion to prevent contact with the surface. In fact, most people don't believe they have cut the food thoroughly until they contact the surface.

When I read you original post, I took your "accidental contact" statememnt to include things like knives banging into each other, into dishes or pans, or into other utensils in the utensil drawer or dishwasher. This happens but is normally incidental.

I totally agree with you that food is accountable for very little dulling.

Bruce
 
bruce :

I guess I wouldn't have called knife contact with a surface supporting the food an "accident".
Click to expand...

Yeah, sloppy wording on my part, carelessness would have been more suitable. If you use a wooden cutting board or a plastic one, dulling is very slow, assuming only necessary force is used, you are looking at thousands of cuts with the lower end steels. The big problem here is cutting with far too much force and mashing the edge into the board, this dulls the knife fairly quickly (it is still hundreds of cuts though).

The very first thing I would recommend to people complaining about poor edge retention in kitchen knives is how they are used and stored. In the vast majority of cases the edge retention can easily be improved by a factor of ten with a few changes in technique and a couple of dedicated beater knives for things like scraping or cutting in metal pans. having a knife made out of S90V won't help if it is constantly cut into steel, iron and ceramic or banged around edge to edge in a drawer.

-Cliff
 
I wouldn't commission a custom kitchen knife. The reason for this is that a high performance kitchen knife has a very thin blade and no bolster. The best way to produce this kind of blade is with a big rolling machine. It would waste a lot of a bladesmith's time (and my money) to produce a great blade. Take a look at a MAC Knife UK-60. It is made from a relatively hard alloy and uses a fully tapered blade that is only 1.5mm thick (about 1/16"). This works great for only $35.00 list and would be virtually impossible for a bladesmith to duplicate.

http://www.macknife.com/page6.html
 
I fully agree with you, Cliff.

Some dulling occurs when the knife is pushed hard into the food (especially sticky food like cheese), then the knife is pulled away from the food at the top but pivots the cutting edge on the cutting board! You can probably reduce your "hundreds" to "tens" when doing this. Always lift the knife a bit off the board before making that lateral twisting motion to break you knife away from the chunk of food.

Bruce
 
Thos MAC knives look very nice however, mainly an issue with Chef's knives but some prefer heavier blades, 3/16" spines with full bolsters, this is mainly for crushing and cracking techniques where more weight and blade stiffness is required. Though I would agree in general that kitchen knives is one area where going custom does little for performance and the cost increase is massive.

-Cliff
 
Even for "crushing and cracking techniques" I see no point in a bolster. This just adds a barrier to sharpening the heel of the blade and therefore the bolster interferes with the full edge contacting the cutting board after sharpening other areas of the blade. A better solution for this work is a chinese cleaver. You can get them with thin blades for slicing and thicker bevels for splitting operations.
 
The bolsters adds weight to shift the balance back, most prefer it to be neutral. You can of course get the same feature without a bolster with more dense handle materials. It also provides a more comfortable finger rest than the back of a very thin blade. This is the same reason why some prefer thicker knives as heavy rocking cuts are uncomfortable on very thin spines, so while the thicker blades are slightly more inefficient at chiseling right through a thick turnip, they are much more comforable while doing so. Bolsters can get in the way with sharpening, but they can also form sharpening guides such as found on the David Boye drop point hunters.

Chinese cleavers are useful for many operations but a stiff Chefs knife is still of benefit in some crushing operations. For example after mincing up fine garlic you crush it with the edge of the blade, this requires a decently stiff knife and doesn't work well with a cleaver because it is too wide and thus the torque disadvantage is heavy. You can of course always pound the garlic out with many other tools, there are a lot of different ways to achive your goals in the kitchen.

-Cliff
 
With the chinese cleaver I use the side of the blade near the base of the spine for crushing operations. I can lean on the side of the blade with the heel of my off hand and apply plenty of force.

I don't see the balance of most knives with a bolster to be neutral. Since the bolster is ahead of your hand it can't bring the balance back to your hand. Typically blades with bolsters are so thick that they are very blade heavy. A thin blade like a MAC UK-60 is neutrally blalance. Take another look at the UK-60 and you'll see that the top of the handle projects over the blade and provides a more comfortable finger rest than a bolster.
 
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