My thoughts after extended cutting with the Large 21.

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uofaengr

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As part of an ongoing project over the past several weeks, I've been cleaning out a junk room that had many boxes left from moving, mail-order items, appliances, wedding gifts, and other odds and ends. In other words, a myriad of different types of cardboard ready to be cut into tiny squares.

My go to for this kind of cutting has been a Spyderco Military for the FFG and comfortable ergonomics, but I thought this would be a good test for the large 21 that's been begging for some work.

I sharpened the S35VN 21 to a very nice 20 dps 1000 grit edge on the Wicked Edge with a few light passes on my KnivesPlus strop block leaving a nicely aggressive edge. I actually started off cutting with a PM2 that I was testing a 15 dps 0.5u edge, but after maybe a half hour I started developing hot spots due to the edges of the scales and the thumb ramp.

I switched over to the 21, and it was actually a relief to my hands. In my head I didn't think the knife would be an ergonomic cutter, but I was wrong. The handles mold into the hand nicely with no hot spots developing, and the jimping is just right for extended use.

My cutting went on for several hours over several days, taking on everything from double wall corrugated to many USPS large priority boxes to that nasty stuff the thick shoeboxes are made out of. I'd cut them into large sections then basically cut each section in half until all was left was roughly a 2" to 3" square or a little larger. I made a point not to strop the edge and would cut phone book paper every once in awhile.

I ended up completely filling a large U-Haul moving box and large Brawny box of equal size with cardboard squares. The second box was maybe less than half of the way filled before I felt that the edge was tearing more than cutting. I then switched back to the Military to finish as I didn't want to stop and resharpen.

This is in no way meant to be scientific, but rather to create some of my own opinions as conjecture based "facts" seem to be the norm. It was a lengthy process, and had to be several hundred cuts, and my wife has yet to figure out why I needed to take so long cutting up these boxes. ;)
As you can see in the pics below, it was a good bit of cutting.

In the end, these are some of the thoughts I left with:
- A sharp hollow grind did just as well as a FFG.
- Easy on the hand and pleasant for heavy extended cutting.
- The edge lasted way longer than what I expected based on what the internet says, and isn't cardboard supposed to be some of the roughest stuff on an edge? What are you people cutting with your knives anyway? Car doors? Same goes for S30V...seriously, what are you cutting? It's a fine steel.
- Just because the edge loses its shaving ability doesn't mean it can't continue to do work. It handled heavy cardboard and paper fine after it couldn't shave until much later when it finally dulled to the point it couldn't acceptably handle either IMO. S30V and S35VN shine with a toothy edge in my experience and maintain a very acceptable working edge for a long time.

These are my opinions; you should always form your own, and YMMV.







 
I honestly don't have a clue what some people do with their knives. Ever hit a staple cutting cardboard, I have on more than one occasion. On one of the knives I have in M390, it chipped the edge. Not bad, but a chip none the less. I've never had S30V, S35VN or CPM154 chip. I've flattened the edge, but never chipped the edge.
Most of the cardboard cutting I do is unboxing plumbing fixtures and household appliances. I try to use the right tool for the right job. It's when I'm lazy that I'll use a knife on hand to open a box.
I've said this before, I think a CRK is the best all around knife made.
Great review, sometimes you have to find out for yourself if what others say holds water.
Enjoyed the pics.
 
Ajack60 said:
I honestly don't have a clue what some people do with their knives. Ever hit a staple cutting cardboard, I have on more than one occasion. On one of the knives I have in M390, it chipped the edge. Not bad, but a chip none the less. I've never had S30V, S35VN or CPM154 chip. I've flattened the edge, but never chipped the edge.
Most of the cardboard cutting I do is unboxing plumbing fixtures and household appliances. I try to use the right tool for the right job. It's when I'm lazy that I'll use a knife on hand to open a box.
I've said this before, I think a CRK is the best all around knife made.
Great review, sometimes you have to find out for yourself if what others say holds water.
Enjoyed the pics.
Click to expand...
Thanks Ajack. I examined what I was cutting pretty good, and did not find any staples anywhere. I sort of wish I'd found one just to see what would've happened.

My first VG-10 Delica I sharpened to 16 dps (factory angle) and used it to process a large, heavy box that a desk came in. I ended up chipping the edge. I don't remember hitting a staple, but it was certainly a strong possibility.
 
nice review. and now you've got tons of inventory for your cardboard shim business.
 
Thanks for taking the time to share your observations. A well written and interesting read. No argument here.....
 
Great review and thanks for your time.
I never cut that much cardboard lol. But I have some of the same results. One thin I can note, is the 21 excels at cutting and slicing over my wifes FFG manix. When shaving and processing wood the hollow grind takes big bites compared to the flat grind which can be great. But control the blade or you will cut deep into

Thanks again! And for allowing me to add totally pointless information.
Matt
 
Well, I suppose if you want a knife that excels at cutting things, being durable, being easy to maintain, and is comfortable to use, then I guess the Sebenza is pretty good.
 
Thats alot of cardboard, put that full box on ebay and see what happens.
How do your hands feels afterwards.
Years ago when ghe Kershaw Boa first came out maybe around 2003 my dad asked to use it to cut something, a. Couple hours latter he gave it back and said you need to get this sharpened. He did the same thing cut up a bunch of cardboard.
I didnt have it a week, its still goin strong though
 
I have had great experiences with crk's s35vn. Its strange that it has such a bad reputation for being soft. It seems a lot harder than the stuff I have cut with it!
 
That's a lot of cuts! I enjoyed your post, especially the part about your wife wondering what took to long:) I too have experimented with different knives for box cutting, and personally found that the sebenza is right up there with the best of them!
 
Nice write up based on your experience. The ergonomics of the Sebenza are deceivingly subtle but become pretty obvious after use. And while I've had knives with steels that held a better razor's edge, they were also more prone to more chipping in my experiences. By contrast, I've never experienced a chip with any of my CRKs over the years. Like others have stated, I'll take the edge rolling or flattening out a bit over a chip any day.
 
I appreciate the kind words and glad you all enjoyed it though I had no intention of being brief. My hand never really got uncomfortable, it was more so my back that would start aching as it was difficult to find a comfortable position to cut for an hour or more at a time. I plan on eventually testing some other knives in a similar manner but a little more standardized for personal knowledge.

I'm not a metallurgist nor steel guru, but when I see people complain about how soft the steel is at 58-59 when it's obvious they've never used the steel, just being trendy and repeating what someone else said, that leads me to have to find out for myself especially if I'm going to refute their claim. And when other huge companies (not Spyderco) put in black and white that they run their S30V at 58-60, I just never see complaints about how soft their steel is since I have a hard time believing every single blade is sitting on 60.0 or even north of 59.
 
My s35v uumnumzann holds a good edge. It just disappoints me when I use it to cut the occasional wire or other out of the ordinary thing. The edge deforms easily compared to some of my other knives.
 
I cut a lot of boxes daily at work, and my amazon boxes at home haha.

Sebenza is great for boxes, but it's massively better when you remove some shoulder and widen the bevel, maybe around 10 degree per side and convex at about 12 to the edge.

It flies through the thickest of cardboard, and even the triple walled wax cardboard is no match for my custom edge.
Polishing also helps it glide through.
I've often hit staples, and even stainless steel tables, it'll flatten since my edge is so thin, but like OP says, it doesn't lose metal via chip.
 
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