Question about the blade shape? The Plunge Line on The Large Sebenza 21

mikepapa1

mikepapa1

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So I was comparing a couple of my Large 21's today (Nothing better to do) and for the first time I noticed that there is a difference in the way the blades are (I don't know the proper terminology) ground? Anyway I have no idea of the significance if any and I am sure it must have come up before but anyway, here are some pictures of a Large Classic along with three Large 21's. One has a Damascus blade so not surprised that it looks similar to the Classic but one of the 21's blade looks similar to the Classic and one does not. Both knives were made in February of 2009, the Classic is from 2007 and the Damascus in April of 2009. All three 21's have code dates of B 08. They are all LNIB with original box, birth card etc. Any observations or comments would be very welcome!! Just trying to learn something about the knives.
All the best, Dave

http://www.flickr.com/photos/105937865@N07/sets/72157641032064315/
 
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Let me preface, I'm very new to CRK. But I've been learning all I can leading up to my recent first purchase. Are you referring to the primary or secondary bevel? Could the variances your seeing in the grind be due to the human/handwork involved? Maybe CRK changed who handled the grinders that year? In the factory video tour of CRK, they primarily eyeball the grinds. No jigs. I'm sure you've seen this video before, https://www.youtube.com/watch?v=Nj6p8p6vfZQ&feature=youtube_gdata_player. Go to 8:40 of this video to see them hand grinding the secondary bevel. Just my 2 cents. I apologize if I missed the mark on your question!
 
Thanks hake!! I apologize for my ignorance when it comes to the terminology used.. Actually what I am referring to is the cut or line in the profile of the grind in its relationship to the front of the handle. If you look at my very poor quality pictures you will notice that the line comes down straight in front of the handle on the Classic, Damascus 21 and the third knife (also a 21) but on the last knife (bottom) it is cut at an angel and disappears into the handle (scale), which is the same way it is on current production models. I never noticed the "straight" line on the 21's before. Again, sorry for the confusion.
All the best, Dave

hake said:
Let me preface, I'm very new to CRK. But I've been learning all I can leading up to my recent first purchase. Are you referring to the primary or secondary bevel? Could the variances your seeing in the grind be due to the human/handwork involved? Maybe CRK changed who handled the grinders that year? In the factory video tour of CRK, they primarily eyeball the grinds. No jigs. I'm sure you've seen this video before, https://www.youtube.com/watch?v=Nj6p8p6vfZQ&feature=youtube_gdata_player. Go to 8:40 of this video to see them hand grinding the secondary bevel. Just my 2 cents. I apologize if I missed the mark on your question!
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I see what you mean now! That is unique! I could be wrong, but I think that's referred to the start of the primary bevel grind. Anyways, not important. But I would hang on to that one. Maybe a rarity?
 
I like the ones where the grind terminates at the edge of the scale or under it with preference to under as it makes the blade appear longer and therefore makes the blade to handle ratio of the knife look more even.

Different guys grinding blades, trial and error of new ideas, constant tweaking of designs, or just plain manufacturing differences- I have no clue, but you'll notice it on every knife now that you've seen it.
 
Dave.
Not sure if this would help but I noticed the same for my 21 Insingo.

y5amape3.jpg
2a7e3yna.jpg
 
Thanks hake! I dont I know why they have two different profiles? Or primary bevel, as you call it, just noticed it and thought it was interesting... especially since both of the plane janes were made a day apart. Bottom knife does have a polished blade with double lugs but other than that they are basically the same knife.
All the best, Dave
hake said:
I see what you mean now! That is unique! I could be wrong, but I think that's referred to the start of the primary bevel grind. Anyways, not important. But I would hang on to that one. Maybe a rarity?
Click to expand...
 
Thanks for your insight Rich! Yea I don't know... :confused: but from what I've seen the bottom example appears to be whats found on current production 21's. So did CRK make the change in the profile of the grind in Q1 of 2009 or does it just appear randomly throughout production? Personally I prefer the first three but I see what you are talking about.
All the best, Dave
1AbominAble1 said:
I like the ones where the grind terminates at the edge of the scale or under it with preference to under as it makes the blade appear longer and therefore makes the blade to handle ratio of the knife look more even.

Different guys grinding blades, trial and error of new ideas, constant tweaking of designs, or just plain manufacturing differences- I have no clue, but you'll notice it on every knife now that you've seen it.
Click to expand...
 
Thanks Ben!! Very interesting!! The knife on the bottom in your photo actually looks different as well! It appears to have the straight grind but it goes further back. As opposed to the last knife in my photos which seems to be at more of an angle? Or am I seeing things? :confused:
All the best, Dave

BenChiew said:
Dave.
Not sure if this would help but I noticed the same for my 21 Insingo.

y5amape3.jpg
2a7e3yna.jpg
Click to expand...
 
mikepapa1 said:
Thanks Ben!! Very interesting!! The knife on the bottom in your photo actually looks different as well! It appears to have the straight grind but it goes further back. As opposed to the last knife in my photos which seems to be at more of an angle? Or am I seeing things? :confused:
All the best, Dave
Click to expand...

Your eyes are pretty good Dave. It is straight and more of a right angle.
Yours seemed to have gone at an angle.
 
I don't know why they differ from model/year/whatever, but I have noticed it as well.

I believe the proper term for what you are speaking about is the "plunge".
 
Cool! Thanks for the information Tripton!! I like it! "The Plunge"
All the best, Dave
Tripton said:
I don't know why they differ from model/year/whatever, but I have noticed it as well.

I believe the proper term for what you are speaking about is the "plunge".
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That is what is commonly called the "plunge line", having the grind or plunge start under the scale is not something I would want to see, personally. It should at least relate to the front of the knife in some way by design.

Looking at BenChew's pictures the lines of the small flow much better than the large with the early plunge, IMO. The knife in question in Mikepapa1's picture looks better, but the grind should start further forward having the plunge infront of the handle and not under it, IMO. It also looks like it was ground by CNC given the "swoop" from the recaso to the flats of the blade. (That can be hard to do well by hand but is a common feature of machine ground blades) :)
 
I am not the detail guy, I am more the bottom line guy as the people that work for me would tell you. But you have me looking more closely at my knives, as few as I have, so here are my Zaan's. Guess what, they have a different plunge line (again I am learning more everyday). The top is from 2009 and the bottom from 2011.

 
I have a variety within my own collection as well! I would guess that is caused by the blades being hand ground, and I think it adds the the uniqueness of each piece!
 
Thanks Haze!! Very interesting information!! Another reason I love this forum!! No matter what the question is there are always members who are willing to chime in and help you!!
All the best!!
Dave

Haze said:
That is what is commonly called the "plunge line", having the grind or plunge start under the scale is not something I would want to see, personally. It should at least relate to the front of the knife in some way by design.

Looking at BenChew's pictures the lines of the small flow much better than the large with the early plunge, IMO. The knife in question in Mikepapa1's picture looks better, but the grind should start further forward having the plunge infront of the handle and not under it, IMO. It also looks like it was ground by CNC given the "swoop" from the recaso to the flats of the blade. (That can be hard to do well by hand but is a common feature of machine ground blades) :)
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Great photos of two awesome knives Bill!! Now I have to check the plunge lines on my Zaans!!
All the best, Dave

Birdhunter1220 said:
I am not the detail guy, I am more the bottom line guy as the people that work for me would tell you. But you have me looking more closely at my knives, as few as I have, so here are my Zaan's. Guess what, they have a different plunge line (again I am learning more everyday). The top is from 2009 and the bottom from 2011.

Click to expand...
 
This has turned out to be much more interesting and educational than I thought it would be!! Especially for a novice like me!!
Thanks for taking the time to respond to my thread Ernie!! The Plunge Line.. very nice! :thumbup:
All the best Dave

Ernie1980 said:
I have a variety within my own collection as well! I would guess that is caused by the blades being hand ground, and I think it adds the the uniqueness of each piece!
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It's interesting to see how the stone wash has changed from 2009 to 2011 as well...finer-grained.

My 2012 25 has a finish that is so polished that you cannot even really see any grain, but it is not satin, either. So smooth...
 
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