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Blade Flex and Sujis

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mr drinky

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I was just reading Stephan Fowler's thread on his new suji (which looks awesome), but there was a comment in there about the (desired) flexibility of suji blades. I didn't want to pollute that thread, so here is my question.

I don't have a suji but will be looking for one come fall, so what are the advantages of one with more flex versus less flex?

For some reason, I have Hung's video in my head where he uses a Misono UX10 suji for a cutting demonstration. Right at the beginning he shows how flexible the blade is by pressing it on the counter. Because of this, I have always thought of sujis as more flexible. Video below.

http://www.youtube.com/watch?v=xwciXwM_5FA

So basically, I am suji ignorant. Anybody have some buying tips?

With that said, in the end I may just go for one of Pierre's or Butch's knives.

k.
 

Dave Martell

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Thin ground knives that are not tall in height and long in length will flex easily, the idea is to not have so much flex that they go where they want, you want them to go where you aim them.
 

Lefty

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I was just reading Stephan Fowler's thread on his new suji (which looks awesome), but there was a comment in there about the (desired) flexibility of suji blades. I didn't want to pollute that thread, so here is my question.

I don't have a suji but will be looking for one come fall, so what are the advantages of one with more flex versus less flex?

For some reason, I have Hung's video in my head where he uses a Misono UX10 suji for a cutting demonstration. Right at the beginning he shows how flexible the blade is by pressing it on the counter. Because of this, I have always thought of sujis as more flexible. Video below.

http://www.youtube.com/watch?v=xwciXwM_5FA

So basically, I am suji ignorant. Anybody have some buying tips?

With that said, in the end I may just go for one of Pierre's or Butch's knives.

k.
I love that video and I know the exact part of it that you are talking about!
When you watch, you can tell he is pushing pretty hard, but Misono stainless (in my experience) can be pretty flexi. I like how my moly gyuto feels because of it's little bit of play and very light feel.
I'll be looking at a 270 suji in the future, and I imagine the flex is far less of a problem than it is with a 300.
You should ask wildboar how much flex is in his 270 (I believe) suji to see if whipiness is an issue (I doubt it is).
 

tk59

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If the knife is a dedicated slicer, there isn't an advantage for the blade to be particularly thin. For an all-arounder, a bit thinner makes it a lot more friendly, imo. How thin depends on what you're cutting, I suppose but I'd say that as long as the tip area is quite thin, it will perform well. Knives that are very thin near the heel feel odd going through heavy, harder objects.
 

Salty dog

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I own two very high end 270 sujis. Watanabe and Masamoto. Niether are very flexible. A little near the tip.
 

Lefty

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Salty, do you have a 300 suji? If so, isn't it much more flexible than your 270s?
I just can't recall anyone complainin about a 270 being too whippy, that's all.
 

Lefty

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Gotcha!
I sure won't ever need a 300, but then again, I'm not a chef.
 

Cadillac J

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I've never had any flex issues with my 270(2) or 300 sujis. They might have a little give to them near the tip like Salty said, but I've never had a blade not go where I want in a cut because of this at all.
 

StephanFowler

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I was just reading Stephan Fowler's thread on his new suji (which looks awesome), but there was a comment in there about the (desired) flexibility of suji blades. I didn't want to pollute that thread, so here is my question.

I don't have a suji but will be looking for one come fall, so what are the advantages of one with more flex versus less flex?

For some reason, I have Hung's video in my head where he uses a Misono UX10 suji for a cutting demonstration. Right at the beginning he shows how flexible the blade is by pressing it on the counter. Because of this, I have always thought of sujis as more flexible. Video below.

http://www.youtube.com/watch?v=xwciXwM_5FA

So basically, I am suji ignorant. Anybody have some buying tips?

With that said, in the end I may just go for one of Pierre's or Butch's knives.

k.
I may have given the wrong impression, the blade in that thread is not dead stiff, I can grab the tip with my fingers and flex it a good inch out of straight pretty easily, it's clearly not as flexy as the knife in that video but it will flex if asked.

it's just designed to be "less" flexy if that makes any sense

Stephan
 

WildBoar

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You should ask wildboar how much flex is in his 270 (I believe) suji to see if whipiness is an issue (I doubt it is).
I may have given the wrong impression, the blade in that thread is not dead stiff, I can grab the tip with my fingers and flex it a good inch out of straight pretty easily, it's clearly not as flexy as the knife in that video but it will flex if asked.

it's just designed to be "less" flexy if that makes any sense

Stephan
My suji is a 300. I can 'flex' the blade laterally ~ one inch if I push on it hard enough. This has never been an issue while carving, although it's possible it moves a little around bones and I just have not noticed. Frankly until I read this thread, I had not even been curious about it.
 

Lefty

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Sounds like it is NOT a problem then :)
 

NO ChoP!

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I have a 300...(Moritaka) zero flex. Yet my 240 does have a little flex.... (I find flex is only good if your going to filet with it)

It seems that when going from a 270 to a 300, it isn't just an extra 30mm added. The entire profile/ geo changes. See Caddy's recent postings comparing his 300 w2 to his new 270 HD. The 300 casts a shadow on the 270.... I found it very interesting.
 

tk59

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Actually, I wonder how much the steel and the HT have to do with flexibility. I recently looked at several laser-types and some flexed a LOT more than others even though the thickness was very similar.

No Chop, I was gonna say that I didn't think Cadillac has a W2 blade but then I realized you meant Hitachi White 2. I was totally shocked at the gyuto-ness of the 300.
 

Kyle

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I recently sold my Konosuke 270mm suji because it was too flexy for my needs. I'm still using a 300mm Kanemasa suji as a dedicated BBQ/brisket slicer.
 

Salty dog

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Yeah, you don't need much flex with a bbq slicer. I used to do it professionally. Believe it or not a big yanagi works pretty good.
 

mr drinky

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If the knife is a dedicated slicer, there isn't an advantage for the blade to be particularly thin. For an all-arounder, a bit thinner makes it a lot more friendly, imo. How thin depends on what you're cutting, I suppose but I'd say that as long as the tip area is quite thin, it will perform well. Knives that are very thin near the heel feel odd going through heavy, harder objects.
This was sort of what I was thinking. A thinner more flexible one might be a better all-around knife (as long as the flex isn't too much that is), but I would mostly have the knife as a dedicated slicer anyhow. I think I would go with something stiffer. I have a 7.5" Forschner utility knife that is quite flexible and use that when I need some added maneuverability around bones. A dedicated boning knife might be in order at the same time. Maybe Dave will even have his butcher set going by then.

Btw, did I hear that Misono knives are stamped, or am I wrong on this? I know they run a bit on the softer side at 59 HRC, but do stamped blades allow for more lateral flex? Just a thought.

k.
 

tk59

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Yes, Misono are not forged. They aren't simply stamped like Forschners are, either. They do taper in both directions. As for the flexibility, I don't know if forging makes a difference...
 

wenus2

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My 300 Harner gives about 1/2" or so at the tip is all, it's perfect for my needs.

I was totally shocked at the gyuto-ness of the 300.
I'm with you, when my Butchihiki arrived (after I got over the initial shock of it's beauty) I took a double take for that same reason. I went over and grabbed out my 210 Kono gyuto and sure enough, they matched up almost perfectly for the first several inches. It makes for a great all-arounder if you have room to work the big bastard :chefcut:
 

Cadillac J

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My 300 [...] makes for a great all-arounder if you have room to work the big bastard
Hell yeah man.

Even with how much I'm enjoying my new 270, I still like to grab my 300 now and then. I don't think I'll ever be able to let it go (hopefully, as I've said this many times before...so we'll see in the next year)
:moonwalk:
 

Lefty

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I'm wondering what the real advantage of a 300 over a 270 would be in a home setting. My 240 gyutos provide all the length I need. I know a longer blade allows for a less disturbed/cleaner slice, but so does being careful and knowing where your edge is. Maybe portioning steaks and trimming out roasts with a utility and a short scimitar taught me to be patient and precise.
Is there anywhere that a 300 will really be better than a 270?
 

Kyle

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Personally, when I'm slicing large briskets I prefer a long slicer. The 270 wasn't quite right for me.
 

tk59

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I certainly don't need a 300 but if I'm slicing something with a tough exterior, sometimes it takes quite a bit of draw before you get through it. Plus, it's an advantage to be cool, isn't it?
 

WildBoar

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My 300 has been good for carving pork roasts (shoulders) and rib roasts. Glad I went with 300 vs 270. Part of me is sad I didn't go for 330! :smile1:
 

Lefty

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I certainly don't need a 300 but if I'm slicing something with a tough exterior, sometimes it takes quite a bit of draw before you get through it. Plus, it's an advantage to be cool, isn't it?
Now I get it! Haha
 

Delbert Ealy

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Actually, I wonder how much the steel and the HT have to do with flexibility. I recently looked at several laser-types and some flexed a LOT more than others even though the thickness was very similar.

No Chop, I was gonna say that I didn't think Cadillac has a W2 blade but then I realized you meant Hitachi White 2. I was totally shocked at the gyuto-ness of the 300.

I was talking about this very subject today, and flex has to do with the geometry of the blade, the steel and the heat treat mean almost nothing when it comes to flex. Its all about the geometry, having said that with flex a very small change in the geometry say .1mm or less can produce huge chages in the flex. Flex is not affected by forging either.
Del
 

PierreRodrigue

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+1 In the fillet knives I do, some guys want very flexible, some like medium, and some stiff. Essentially, the only difference in the knife is the geometry of the grind, I use the same starting stock, and the HT is the same. Final hardness is within 1 point. You can really affect the flex, with minimal change to the geometry.
 

StephanFowler

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I was talking about this very subject today, and flex has to do with the geometry of the blade, the steel and the heat treat mean almost nothing when it comes to flex. Its all about the geometry, having said that with flex a very small change in the geometry say .1mm or less can produce huge chages in the flex. Flex is not affected by forging either.
Del
yep, I had a long long conversation with Kevin Cashen at a hammer in once about the modulus of elasticity and he proposed an "experiment"

I took several bars of 1/8 x 1" 1084 and clamped them horizontal off of a table with 12" hanging off the table.

one bar was not modified at all, one bar was given a very thorough anneal, one bar was heat treated in oil, one was heat treated in water

a 50Lb weight hung off the end of the bar produced the exact same amount of flex in each and every bar.

so I re did the test, using 5 samples all ht'd together and tempered to the same hardness
one, piece was left in it's original shape, one piece was given a distal taper, one was beveled, one was beveled and tapered, and the last was convex beveled and tapered.

all of them flexed differently - again, the only measurable difference between the 5 samples was the grind
 

WildBoar

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uh oh -- previous post needs moderator approval. I'm guessing theat's due to the link :(
 
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