CRKT Point Guard

C

Cliff Stamp

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The CRKT Point Guard has a drop point blade stock ground from AISI 420 stainless steel. It weighs 120 g, with a blade 3.125" long, the OAL is 4.75" when closed, the handle is a massive 0.5" thick with 420J2 double stainless steel liners, a 6061 T6 hard anodized aluminum back spacer and Zytel scales. The knife has a liner lock with LAWKS safety latch and a ball detent and opens with use of a thumb disk.

The knife is very comfortable in hand, with one of the most comfortable clips ever felt, it curves gracefully with no squarish points to cause excess discomfort. The very aggressive cutouts across the lock and at the top of the handle are very secure but high in discomfort, they are not optomized for extended cutting but rather brief periods where high security is desired.

The blade has a high flat grind and the edge is 0.020-0.030" thick ground at 20 +/- 2 degrees. The initial sharpness was average, little shaving ability but could scrape some hair, on light thread it scored 159 +/- 11 g, well under optimal. On 3/8" hemp it took 55 +/- 2 lbs on a push, no aggression on a draw. For comparison the Spyderco Manix was initially 90 +/- 14 on thread and could slice the hemp with 15 +/- 1 lbs, took 7-9 lbs on a two inch draw offering a much higher level of sharpness and cutting ability.

The Point Guard will be used for some edge comparisons against a few standard blades, VG-10 and possibly S30V after being used for awhile as just an EDC blade. The edge will likely be profiled before the cutting comparisons because the edge as now is too obtuse for ease of sharpening on the Sharpmaker and the comparison blades have much more acute angles.

In regards to the lock, the liner is secure under white knuckling and spine whaks and light torques, with the LAWKS safetly catch engaged it looks to be near impossible to disengage the lock without applying enough force to simply break the lock apart. However it looks like the LAWKS system could be prone to disengagement on heavy stabs or cutting through loose material.

-Cliff
 
Cliff,
The new (05) CRKT Point Guards show a blade steel of...ugh :barf: ...420J2. I was disappointed, to say the least, with CRKT's move to switch the blade steel on a lot of their knives from AUS6 to AUS4 and 420J2. It appears as though they have switched all of their Crawford and Ryan collaborations to 420J2, while either raising the prices or keeping the prices the same :rolleyes: .

What's your take on CRKT's move to 420J2? Maybe they figure the liner-locks won't wear as fast with the blade steel and the liners sharing the same steel :D . I'd be very interested to get your take on how the AUS4 and 420J2 CRKTs perform.
 
You are right it is AISI-420 just checked my emails, I was just going off of some internet spec's. Does anyone know what carbon percentage they are using, surely it isn't stock 420? Are there any hardness quotes?

-Cliff
 
Cliff,
I am lucky to have the older AUS 6 Point Guard. Having had them for about 3 years (is it 2?) still working fine, though I used it mostly on light cutting (i.e. paper, cloth, fruits).

Tell me how the newer one performs? I believe AUS 6 will do better than 420?

Here it is taken from CRKT website:

6763: Combined Razor-Sharp and Triple-
Point™ Serrated Cutting Edge
MSRP U.S. $54.99
Buy from A.G. Russell | Chesapeake | Travel Country

Blade: Length: 3.5” (8.9 cm)
Thickness: 0.14” (0.35 cm)
Steel: 420J2, 54-56 HRC
Closed: Handle length: 4.75” (12.1 cm)
Open: Overall length: 8.25” (21.0 cm)
Weight: 4.3 oz. (122 g)
 
Thanks for the specs.

Before altering the edge I used it for some harder work, cutting up knots, very hard and thick plastic and even light metals, pop can's etc. . The knife handled that well, it went blunt very quickly on the metals but did resist damage well. This is work I would not want to do with something geared towards pure cutting like a Boye folder.

I then reprofiled it, it worked easily, while I would not want to have to file it to shape, it ground easily on belts. The edge was really uneven, one side was at about 15 and the other at about 25 before reprofiling to a uniform 10-12 degrees per side.

Sharpening was difficult, the steel was really floppy, even on the flats of the ceramic Sharpmaker hones it would just burr from one side to the other readily. I finally got a decent shaving edge, but not what I would call really sharp. The cutting improvement on hemp more than doubled with the more acute edge and higher sharpness.

I will now use it as an EDC for awhile to get a feel for sharpening it and how it handled before doing some side by side testing. Already though the initial high thickness of the edge and greater angle plus softer steel are a problem for utility and general cutting, this seems geared more towards harder work.

-Cliff
 
Cliff Stamp said:
Does anyone know what carbon percentage they are using, surely it isn't stock 420?
-Cliff
Click to expand...

Yep, their steel FAQ in their "05" catalog lists "420J2" Carbon at "0.15", but the steel FAQ on their website: http://www.crkt.com/steelfct.html lists "420J2" Carbon at "0.32".

I eagerly await your review of the Manix, as I love that knife :cool: !

Thanks,
3Guardsmen
 
I own a cheap chinese copy of Buck 110, with a steel so soft (I bet it's softer than the new CRKT 420J) and as Cliff says, keep forming burr side to side.

So I did a more drastic way: convexing the edge. It holds up quite well, not able to shave, but can slice 80gram A4 paper without support (hold paper with left hand, slice from top to bottom with right hand). Cliff, I suggest you try convexing it or put a light obtuse angle on the edge, by pushing the edge into the stone at higher angle. It will help removing the burr quickly.
 
Yeah, I should switch to sandpaper to reduce pressure on the edge as now the 20 degrees Sharpmaker setting is just burring it, even with light pressure on the flats. It does cut well now though and a very stainless steel is nice in the kitchen. I would really like to see a thinner edge NIB, 0.030" is what I would put on a large bowie meant to baton through knots.

-Cliff
 
I ran a quick check on the edge retention on this last night with the adjusted profile, 23.5 m of 1/8" ridged cut and the blade still had lift left in it. Ten passes per side on CrO loaded leather and it was back to shaving sharp. That was a lot of carboard, so the edge retention at first pass isn't horrible.

-Cliff
 
You may be seeing the results of the thinned edge not just the wear resistance of the steel. Since the thinned edge should cut cardboard much better than stock configuration it has that much further to go until it is functionally dulled. Some knives, especially something thin like an olfa utility knife can cut through cardboard much longer than the material properties of its steel would suggest.

In effect you have to reduce performance to the point of stock geometery before the performance of the knife can be compared to stock in terms of edge retention.

This also applies to the ease of sharpening as well, a fresh edge or microbevel is much easier to apply to a thinner edge simply because there is much less steel to remove and the thinner edge is easier to align than a thicker edge.

As well, note that cardboard can vary hugely between clean samples, also much of its abbrasiveness is caused by dust and trapped micro-inclusion, so that when comparing the results the results seen here to another cardboard cutting round, the results could be very different just because the cardboard is different. This inconsistency in substrate is also a factor in cutting used carpeting, where dirt and other inclusions can lead to rapid dulling and even micro-chipping.

Something that may be helpful is a direct comparison on a very common knife of similiar edge geometery, like a properly sharpened SAK or Opinel would make the reults more meaningful to many readers.

Not a criticism of your work here or the results at all, just things to note when interpretting the results, as well as noting the consistency and condition of the cardboard (1/8" Cardboard comes in many flavors). Also, how much of the blade was used (was testing confined to a 1" segment or was the whole 4" balde used), was any draw used to add a slicing component and was the blade held at 90 degrees to the cardboard or was it sliced at an angle so that shear was a factor?

Edited to add: Today, I was thinking about how edge geometery effects edge retention and my post above. It is worth noting that my comments above are based on relatively soft, abrassive materials being cut, where the dulling is literally the edge being slowly worn away. In other types of cutting, such as hard palstics, light metals, hard wood where the method of dulling is likely deformation (edge roll, dent, etc.) a thinner edge will usually have lower edge retention than a thicker edge profile. The thicker edge profile's increased cross-section results in markedly higher strength (which by definition is the ability to resist deformation) and thus will have greater edge retention when cutting hard materials.

This just illustrates that knowing what you want to use a knife for is a key factor in determing what steel, gemeotery, blade pattern, etc is optimal for your use.

Again, nothing is meant as criticism of your work (unless it is constructive) just questions that may help the reader to interpret the results.
 
Cliff Stamp said:
In regards to the lock, the liner is secure under white knuckling and spine whaks and light torques, with the LAWKS safetly catch engaged it looks to be near impossible to disengage the lock without applying enough force to simply break the lock apart.
Click to expand...

In all likeliness, the LAWKS will simply fold under heavy "Stampesque" ;) impact well before the lock itself accidently disengages.
 
knifetester said:
Since the thinned edge should cut cardboard much better than stock configuration it has that much further to go until it is functionally dulled.
Click to expand...
Yes, this is why you need to do a sharpness test not just simple a gross cutting test, you can incorporate this into the cardboard cutting if you look at the way it cuts, look for tears and such, many of the rope cutters in the ABS do it that way, but I really prefer to do it independently with thread or light cord.

This also applies to the ease of sharpening as well ...
Click to expand...
Yes, severely here in particular. The initial bevel was so lopsided it would have taken about an hour or more to set the edge on the Sharpmaker, I really wish people would put more work into initial edge geometry, not as much sharpness but just shape. Here it was a quick stropping to create a micro bevel, to check and see just how much wear had taken place. If I had kept the origional bevel I would have micro-beveled at around 25-30 in the same time.

As well, note that cardboard can vary hugely between clean samples...
Click to expand...
Yes, that is why I usually run multiple blades at the same time and randomally select the cardboard. However if you do a random selection on a large selction you can compare from one trial to the next, but I prefer to do them at the same time. The above was just a quick qualitative trial, mainly to see if the blade was essentially terrible or not. To do a more quantitative comparison I will need to gather a much larger supply of cardboard.

-Cliff
 
I used to carry one until I broke the tip, mine is AUS 6. It is a nice knife. Comfortable, solid, and cut pretty well. The only thing I disliked about it is the grooves cut in the side would pick up dirt and the oil/sweat from your hands which would get pancaked in their. In needed to be cleaned or it would get to be pretty disgusting. I wouldn't use it as a food prep knife.
 
I don't like all the speed holes in the handles either, a lot of people like that though, or must anyway as a fair amount of knives get fancied up in that manner.

I really didn't like the opening ramp either initially, but after carrying it for a few days it grew on me, it opens now just as fluid as the holes on the Spyderco's, just need to get used to it.

-Cliff
 
Cliff Stamp said:
The Point Guard will be used for some edge comparisons against a few standard blades, VG-10 and possibly S30V after being used for awhile as just an EDC blade.
Click to expand...

I would like to see it tested against basic steels as well like AUS6, 440a, or 420HC. Ideally 3 levels of steel, low/medium/high (ie, 420J2 vs. 440a vs. VG-10). VG10 will blow 420j2 away, but I would like to see just how much worse 420j2 is than other manufacturers' basic steels.
 
As a second and more extended test I ran it against a Cold Steel large Voyagar in AUS-8A, both had the same modified edge angle and were finished on the fine Sharpmaker rods, 20 degree per side setting.

The knives were first used to make shavings off of 1x2" pine moundling, 20 cuts were used to make a two inch point. After the cutting the knives could still slice fine newsprint. No evidence of edge degredation.

The knives were then used to scrape along the sides of the wood, creating light tinder, 100 passes were made with each blade. Again, no blunting was noticed on the knives.

The Voyager and Point guard were then used to slice 1/8" ridged cardboard using a two inch section of the knives, 21.5 cm of cardboard were cut with each slice. The edge retention was again tested on newsprint after 10,30, and 70 cuts for a total of 15.1 m.

After 30 cuts the Voyagar could be noticed to be leaving the edge slightly rough, afte 70 cuts it was more significant while the Point Guard was still smooth, however both were still cutting well, able to draw across the paper and then continue down making a cut with no tears, and then cut into the side at an angle readily.

I then did a quick test on the thread which showed the Point Guard at 286 (33) and the Voyager at 287 (29), no significant difference which isn't surprising as that is a fairly uncertain measurement and you would have wanted to do it all along to draw a sensible strength conclusion.

It is interesting though that at worse the Point Guard is able to stay with the Voyagar and at best is slightly ahead. I'll repeat this with more cardboard later on, plus I have a Cold Steel Vagabond (AUS-6A) which I'll throw into the mix as well.

-Cliff
 
I bought a Pointman Minor with the AUS-6 steel. It was not great steel at that. The knife actually fell apart in my pocket one day after a few weeks of carrying it. The clip kept comming off and the scales got loose so i had to keep them tight. The worked themselves so loose one day that they fell off and I lost a screw.

I sent the knife back to CRKT and demanded a new one. I then took the the new one back to the dealer I bought it from and had him trade it in on a Benchmade 885sbt.

This knife was so poor that it soured me on CRKT until just recently when I decided to buy a M-16 from a fellow board memeber. I hope the M-16 works a little better than the Pointman.

I would consider the Pointman I had to be the worst knife dollar for dollar I ever had. I think I paid about $35-40 for it and it preformed like a $5 POS.

Just had to share my one story about a bad knife I had.
 
3Guardsmen said:
Yep, their steel FAQ in their "05" catalog lists "420J2" Carbon at "0.15", but the steel FAQ on their website: http://www.crkt.com/steelfct.html lists "420J2" Carbon at "0.32".
Click to expand...

I am certain their website had it listed at the lower .15 level when they first added 420j2 and the other new steels. I remember complaining to them about it and specifically noting the Carbon level listed on their own website.

They must have changed it, hopefully to accurately reflect a custom 420 steel they are using. There are definitely more than a few different steels out there labeled 420. I think some European knives are made with something called 420 (although they usually use a 1.___ designation instead) but with more Carbon than 420J2. However, I thought 420_J2_ indicated a specific steel (ie, with the low Carbon).

Cliff's tests so far suggest something different from standard 420J2. However, while the tests sounded trying, it also doesn't sound like either blade took much "damage." Not breaking damage, but I would like to see one get dull enough to not cut much.
 
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