The “sandbag test” and my new Sebenza

[FNFALFAN]

One of the toughest ‘tests’ for edge retention on a knife I have come across is cutting through bags of sand. This will dull the best edge quite quickly and has always given me a good idea of how the blade will perform/hold an edge under continuous use on lesser demanding surfaces too.

The Test: Open 50lb bags of standard ‘playground’ sand (placed flat on the ground) by plunging the blade into the bag and dragging the knife through each bag lengthwise. As you pull the blade through the bag, draw the knife back out of the bag so the entire cutting surface is exposed to the wear of the sand and is required to cut the bag. The tip will be exposed to the greatest wear. As you are cutting each bag make note of how easily each cut is made and how ‘clean’ it is. After each cut note the condition of the blade. Look for chips, scratches, and how sharp the edge is (by feel). See how many bags you can cut before you are really just tearing/gouging them open. When you reach a point you are using a sawing motion (not just a draw cut) stop. By this point the edge will probably be quite dull. Then take note of how much work it takes to return the edge to ‘hair popping’ condition.

The Standard: The average Benchmade or Spyderco Endura/Police (I have tested) will go through 5-6 bags before it’s just tearing. Most serrated/semi-serrated models fair better as they retain the ability to cut (saw really) with minimal effort after the ‘standard edge’ ones fail (about 5 more bags worth of ‘cutting’). They will normally return to a ‘hair popping edge’ within 40 strokes (per side/per stone) using the Spyderco V sharpener.

The Sebenza: While I have owned 100’s of knives this is the FIRST CRK blade I have ever owned. I just traded into a LNIB (born in 99) standard (non-decorated) Large Sebenza that is ‘semi-serrated’ (about 1/3 of the blade). Please note; I strongly prefer semi-serrated models as they retain the ability to cut (saw really) with minimal effort, even under really hard use. The Sebenza was able to draw cut through 13 bags before I needed to use ANY sawing motion to gain a clean cut!!!!! Using the serrations, I was then able to ‘cleanly open’ another 10 bags without too much problem!!!! By this point the edge was REALLY dull (i.e. you could garb and squeeze it with a good deal of pressure without getting cut). It also had no nicks or ‘discernable’ scratches after the test. It took me 65 strokes (per side/per stone), using the Spyderco V sharpener, to get it back to its ‘hair popping edge’. I’m sure with a little stropping the edge could be a little ‘finer’ but it’s not necessary to the overall performance. I’m going to give it a good cleaning this evening (it’s nice to have a knife you can take apart to remove grit!) and that should return it to its LNIB condition.

AAR: In my opinion the Sebenza is EVERYTHING and MORE than it is advertised to be! It locks up tighter than ANY folder I have EVER seen and is EXTREMELY safe under hard use. It is also smoother when opening/closing the blade (provided you use a grease type lubricant!) than most others I have seen. It holds an edge quite well and sharpens with reasonable effort, even from a completely dull edge. It is also one of the most ‘comfortable’ knives I have carried. When clipped to the pocket of jeans/slacks, light shorts, and even IWB in sweat pants it is not ‘noticeable’. This is mostly due to the fit and finish of the knife, as all of the corners are rounded and edges broken. Kudos to CRK on designing an outstanding product!

In Closing: While I’m not going to toss out the rest of my EDC knives (yet), the Sebenza will undoubtedly be the #1 choice for EDC going forward. This knife is exactly like my Steyr Scout rifle, in so much that unless you own one you will not understand why it’s a ‘must have’ tool. On a related note, my CRK Project 1 arrives in the next few days (per UPS) and I will let you know what I think. I’m sure it will be a winner!

PS: Has Mr. Reeve been made a Saint yet? If not, lets at least consider a Nobel Prize…

 

[chad234]

Nice work, I always like to hear about a knife being used as it is supposed to be rather than sitting in a safe.
How much of the increase in cutting life (edge retention) would you attribute to the abrassion resistance of the CRK heat treated bg-42 (relative to the other steels) and how much to the thin hollow grind (a super high performance grind compared to the average production knife i.e Benchmade)
Take care,
Chad

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Wicked Knife Co.
Hoods Woods
chad234@email.com

 

[FNFALFAN]

Thanks Chad! I understand the ‘collector’ mentality (i.e. if I had a decorated and gem studded Sebbie it would leave the house) but my knives are all ‘users’ and should perform as such. Therefore some testing is in order before they are 'pressed into service'.

To answer your question, I feel it is really a combination of the quality steel, with the proper temper, as well as having a sound blade grind, design, and geometry for the application that make the Sebenza perform so well. This is actually the criterion that merit success or failure in ALL knives by ALL makers! There are several collieries that I feel apply in this case.
1.You can apply the best grind and geometry to a blade of inferior steel or improper heat-treating and you will not have much success. Anyone who has handles a ‘Pakistan lock back’ will attest to this. The general design/grind of most of the ‘Pakistan lock backs’ have served well in other ‘sporting knives’ throughout the years (e.g. Buck, Schrade, and Case all use a similar design for their classic locking folders but with quality steel) but when combined with poor quality steel they are still crappy knives.
2. Even the best steels in the world, heat-treated with the highest quality control, won’t perform as well if the geometry/grind used is inappropriate to the requirements of the design itself (e.g. heavy chopping vs. general use vs. surgical instruments).

Based on the fact that these knives are in the $300 + range, one would assume that CRK would first assure that only the highest quality materials, best design characteristics and top flight workmanship are used in the production of the Sebenza as well as their other products. As a secondary consideration, the pricing strategy would then be based on production, material, and ancillary costs. This is not to say that CRK designs and markets their products with money as no object! However, I’m sure that they realize that their customer base has a ‘higher threshold’ for price vs. quality than the average ‘market customer’. As an example a relative of mine carries really cheap Spyderco copies made in Taiwan. He also uses them as screwdrivers and pry bars therefore he breaks a bunch of them. He cannot understand why I would own a $350-$400 ‘pocket knife’. Yet he buys dozens of the cheapies (for about $3 bucks each) and destroys them quickly. This is what I would call a ‘low threshold buyer’. They don’t want to spend $ for quality when they can have quantity. It’s a product of the ‘fire and forget’ or ‘single serving’ society we live in. Spyderco and Benchmade produce some excellent knives, as do many other standard brand makers. But they are designed (for the most part!) with the ‘midrange shopper’ in mind (e.g. a really decent knife for a good price). One would then draw the conclusion that their blades are designed with quality materials, design characteristics and workmanship that can be had for “X” dollars. Each product has to fit into their pricing strategy and still give adequate service life. This is NOT to say they make a bad product! But for the most part you get what you pay for and performance should be a big part of the package. Most folks that eschew the purchase of a $350-$400 ‘pocket knife’ will spend 2 times that in a lifetime on ‘lesser knives’. Thus it’s reoccurring cost vs. a fixed price scenario. In a nutshell, the abilities of the Sebenza are based on the ‘sum of its parts’ performing to specifications that are targeted (by CRK) to exceed industry standards by a wide margin. Therefore its performance is, while reassuring, not too surprising. Mr. Reeve and company ‘did their collective homework’ and we are reaping the rewards in the form of ownership of a well-designed and executed product. Buy quality and only cry once….

 

[chad234]

Great post.
So you're happy with the Sebenza, right?

 

[FNFALFAN]

To say the least! It is really a fantastic knife.

I feel especially lucky to have traded into a semi-serrated large Sebbie in NIB condition. While I’m not ready to toss my LCC/DA and Spec. Svcs. Folder out, the Sebbie has certainly 'made the cut' for the EDC class. I’m currently awaiting the arrival of a new Project 1. Which, UPS willing, will be in hand tomorrow. I will let you know if it lives up to the CRK reputation. I rather expect it will and then some...

 

[craigz]

Am I the only one wondering how FNFALFAN explained away 40 or 50 slashed bags of sand?

 

[OwenM]

Glad to see a Seb being used hard instead of being a drawer queen.
It was just regular sand? Did something similar awhile back, but not with a Seb.
On the job, I reworked several pallets of Particle Mineral Fiber which is slag wool fiber ground to a consistency similar to sand. It is highly abrasive.
I opened over 325 50lb. bags in a manner identical to what you describe, except that I also made cuts at the top and bottom perpendicular to the lengthwise cut-made it easier to dump.
The knife was still cutting at about 85-100 bags (I do not know at what point I had to start "sawing" with the blade, but the cuts were clean), and was basically ripping them open after that.
The knife was a BM 710HS in M2. There were no scratches, but the finish wore completely off from the thumbstuds forward after less than 40 bags.
Only reason I mention it here is that my perception (from comparable use day to day) is that my small Seb holds an edge better than my M2 710. I know the 710's recurve outslices the Seb, but don't know if that affects edge-holding. If I ever have to do this again, I'll use the Sebenza, and see how it does-but I'll stop when it stops cutting rather than totally ruin the edge.
Here's a scan I took after the fact:

Not a good scan, but it shows the wear.
How did the Sebenza's stonewash finish hold up to cutting the sandbags? Or is it gone?



[This message has been edited by OwenM (edited 05-22-2001).]

 

[OwenM]

Chad,
I have an opinion on high performance grinds affecting edge-holding.
It makes sense to me that a knife with a thinner, higher grind requires less effort to perform the same task, so the edge is under less stress (since less force is needed). Less pressure should equal less wear which should equal more edge-holding, everything else being the same (blade length, steel type, etc.).
Something I've been thinking about, lately (and it sounds pretty good to me at 3 a.m.

).

[This message has been edited by OwenM (edited 05-22-2001).]

 

[Davis147]

Sebenzas are tough but to stick a blade that costs any more than a rusty nail in to a sand bag is not an appropriate use of the tool. (I was going to swear and mention stupid but thought better of it).
Redrags
tink

 

[K-guy]

I guess you didn't think too hard Davis147

. Thanks for that great test FNFALFAN!

I'm glad someone has the guts to put this great using knife to the test. I don't feel this was too extreme of a test. I carry and use a large wood inlayed Sebenza daily and love it. I wouldn't even think of sticking it on a shelf somewhere just to look pretty. This knife is meant to be used...and hard!

 

[FNFALFAN]

Actually I was opening a bunch of sand bags so we could finish a buddy’s walkway, in front of his home. We were using the sand to level the bed before we put in the ground tarp (which I also cut with the Sebbie), pea-gravel and stepping-stones. I do not go randomly to Home Depot to ‘gut’ bags of sand…

The 'stone wash' on the blade of the Sebbie was almost totally unaffected by the test… So I’m impressed on that account too!

“Sebenzas are tough but to stick a blade that costs any more than a rusty nail in to a sand bag is not an appropriate use of the tool”. Well friend I don’t buy ‘high speed low drag’ knives just to cut cheese and open the mail. Yes, I may be called a real ‘knuckle dragger’ for exposing the Sebbie to some harsh work environments but in my opinion, if you buy a $350-$400 ‘pocket knife’ and it can’t be used while gardening and DIY work (not to mention cutting cheese and opening the mail) you were screwed! Abuse falls under prying with the blade or using it as a screwdriver/hammer. I carry a SAK and Spyder Wrench for those tasks.

Speaking of which, I would LOVE to see a CRK multi-tool!

It would likely cost $1000+ and collectors would publicly flog anyone caught using one to open a beer but it would probably be able to twist the gun turret off a battleship! It would of course come with the options of wood side finish, inlaid gems, all damascus steel, and 24kt gold bass-relief carvings by Claude DuBaine.

 

[Nemo]

Hello,

M2 blades are really good for abrasion test...
BG42 is excellent when used hard.

cheers,

JM

 

[OwenM]

<font face="Verdana, Arial" size="2">Originally posted by FNFALFAN:
“Sebenzas are tough but to stick a blade that costs any more than a rusty nail in to a sand bag is not an appropriate use of the tool”. Well friend I don’t buy ‘high speed low drag’ knives just to cut cheese and open the mail. Yes, I may be called a real ‘knuckle dragger’ for exposing the Sebbie to some harsh work environments but in my opinion, if you buy a $350-$400 ‘pocket knife’ and it can’t be used while gardening and DIY work (not to mention cutting cheese and opening the mail) you were screwed!</font>

Preach on, brother.

<font face="Verdana, Arial" size="2">Speaking of which, I would LOVE to see a CRK multi-tool!

It would likely cost $1000+ and collectors would publicly flog anyone caught using one to open a beer but it would probably be able to twist the gun turret off a battleship! It would of course come with the options of wood side finish, inlaid gems, all damascus steel, and 24kt gold bass-relief carvings by Claude DuBaine.

</font>

LMAO

Glad to hear the stonewash finish held up. Mine has lots of scratches, but I haven't noticed any real "wear" as in the finish fading or being polished off from use.

 

[rdangerer]

Bags of dirt will also dull a knife very quickly if opened in the fashion mentioned.

I realize you may have set out to test the BG-42, and that is a good thing.

After noting how awful dirt was on numerous blades (AFCK in ATS-34 & 440V Starmate), I decided to be less of a bull-in-china-shop and more of a surgeon ... I cut the bags with blade upside down, like opening up a deer's gut, so the blade didn't make contact with much dirt, just bag. Kinda helped edge retention.



[This message has been edited by rdangerer (edited 05-29-2001).]

 

[FNFALFAN]

I haven’t had the opportunity to fully ‘test’ my new Project 1 as of yet. I received it about 2 weeks ago and it’s still in the ‘touch and grin wickedly’ phase

(which seems to last for quite a while with all CRKs, including the Sebbie). I’m looking forward to taking it out while hunting or shooting to see how well it does at the ‘mundane tasks’ in the field. IMO, if you don’t own one of the fixed blades (i.e. the One-Piece line) you really should get one, they are an awesome piece of work to behold! They are also a lot better balanced than they look.

I do ‘use’ my EDC knives but tend to really ‘keep them up’, at least after they have proven themselves ‘worthy’ of being depended upon. I opened a few boxes today with the Sebbie and then immediately removed the sticky ‘gunk’ off the blade, once clean I checked the edge (SHARP!!!) and re-oiled it before returning it to my pocket. I must admit that I had to chuckle a bit when thinking about some of the poor folks who probably read ‘the sandbag test’ and pictured me more as a ‘callous abuser’ of ‘such a fine tool’. In truth I’m quite the opposite! I LOVE my Sebbie, take great care of it (as with all my tools/toys), and prefer it at my side…

However, I’m still one of those ‘use it first and then tell me how you like it’ types. Whether it’s a folder or not CRK builds one heck of a knife!


[This message has been edited by FNFALFAN (edited 05-30-2001).]

 

[The General]

. Whether it’s a folder or not CRK builds one heck of a knife!

Never a truer word was said

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