Agent : Bob Dozier

[Cliff Stamp]

This is a small tactical/utility from Bob Dozier. The knife was used extensively for an extended period of time, by me and friends. The review is based on that, stock work, and direct comparisons against other blades.

While this knife worked well as a small utility knife, it would readily be outperformed directly by something like the Deerhunter. The Agent is ground out of thicker stock which does make it stouter, but the steel was very inflexible and the tip snapped readily during carving of a small bowl.

Personally once the steel thickens and the scope of work starts to include prying or anything harder I would look towards simpler steels, or make the knife really thick like the H1.

In regards to the performance, the NIB edge had problems with low sharpness and inconsistency of angle which lead to a complete profiling. The sheath also flattened the edge until the edge was wore down enough through repeated sharpening that it didn't make contact anymore.

There was also an extended EDC comparsion edge retention wise, plus a series of tests on cardboard vs the Safari Skinner from Swamp Rat and both were near identical on cardboard and the Skinner much more durable with respect to fracture (idential edge profiles) in general.

Before using the knives I wondered about security with the smooth grips and this was indeed an issue. With a clean handle and a fresh hand it wasn't a problem, but with any contaminant it was difficult to keep control of the grip as the retention was low and doing a hard stab simply wasn't practical.

I will be repeating the edge retention comparison with a K2 to see if it is consistent and looking at work similar to the retarded mauling of the Skinner by Eric and company in the upcoming week, ref :

http://www.bladeforums.com/forums/showthread.php?t=322561

Link :

http://www.physics.mun.ca/~sstamp/knives/agent.html
http://www.physics.mun.ca/~sstamp/knives/reviews.html
Note the K2 didn't have the initial edge problems or sheath issues as did the Agent.

-Cliff

 

[Howard Wallace]

Cliff,

The pictures in your review are not coming through for me.

 

[knifetester]

I am very suprised by the low intitial sharpness you report, I have owned several Dozier knives and all came very sharp.

Why did you choose a tactical model over one of his hunting knives? The hunting and outdoors knives have deeper hollow grinds and thinner edges, and therefore higher performance on the types of chores you would use a small knife for.

Did you notice any difference in wood carving that would be attributable to the hollow grind compared to a flat grind of the same edge geometery?

 

[Cliff Stamp]

I am very suprised by the low intitial sharpness you report, I have owned several Dozier knives and all came very sharp.

The sheath was more of a concern, plus the lopsided edge. Sharpness isn't as much of an issue as sharpenability.

I did see what I expected in regards to aggression, which was something I had been interested in for a long time. His D2 was hyped for a long time mainly by users as heat treated for edge aggression, just like Boye's steel, and just like Boye the edge is left sharpened with a very rough finish which gives a high slicing ability, not due to some property of the steel.

Dozier does combine a high shaving ability on the K2 with the same rough finish which is nice because too many people believe that if you leave the finish rough then it can't be made to shave, which it can, the edge just needs to be crisp and free of burrs.

The hunting and outdoors knives have deeper hollow grinds and thinner edges, and therefore higher performance on the types of chores you would use a small knife for.

I have one of those as well, the K2, review is in progress, performance is pretty much just as you have noted. He makes a lot of designs which are near perfect for D2, I would prefer a more secure grip though and the ability to remove the clip on the sheath as it rides well as a neck sheath or directly in pocket as it is so flat.

The Agent was interesting to use because I really don't see D2 for that type of knife, certainly not at ~60 HRC so the Agent provides a differing opinion. I didn't see anything here that would change my mind however.

If you move outside of cutting then you look at stuff like batoning through hard materials, prying, digging, and in general rougher work with more strength and less skill - if you are not doing this then why have the thicker grind.

Now it is obvious that the Agent is more durable than say the Deerhunter in D2 as it is significantly thicker in cross section so it has a wider scope of work, however I just don't see it as being wide enough and the steel inherently unsuitable for that work.

Plus I really don't like that kind of work with those types of steels because there is no warning to failure. I broke the tip of the H1 digging in woods and it is much thicker, but again stainless and similar steels have little deformation before fracture at ~60 HRC. They are near perfectly rigid and then they break.

If you are going to use D2 like that then P.J. Turner runs it well. He leaves it fairly soft to get the impact toughness up, so you can hammer on and with it.

Before and during this review I asked several people who promote his knives for suggestions on what to do with this particular knife which would showcase its ability compared to a few other knives, I got no responces. I still have the knife so the offer still stands of course.

Did you notice any difference in wood carving that would be attributable to the hollow grind compared to a flat grind of the same edge geometery?

If the edge geometries are similar, the hollow grind would have better performance but not significant as drag is really low in carving, more of an issue in chopping as wedging can exert high side forces, in carving the chips curl away from the blade so the edge and thickness of the primary grind are of most importance.

The images are being irritating, they all have the same permissions in the same folder. Yesterday some would come in for me (when looked through an outside connection) and some would not. The main server has been having problems lately and they are resetting settings trying to fix it. Hopefully it will get worked out soon.

If images don't come in you can try doing a link copy on them and trying to open the link directly. If this works it will go in the cache and then be included in the review the next time it is refreshed. If it doesn't work, drop by mun and hit one of the sys admins with a large magnet.

-Cliff

 

[T. Erdelyi]

Isn't D2 notorious for being brittle?

 

[Cliff Stamp]

D2 is one of the more brittle tool steels, it has little flexibility and will tend to splinterize when it cracks, producing many fragments if you bend it to failure or impact it. It makes a nice light utility cutting steel, scraper etc., high wear resistance and decent hardness.

-Cliff

 

[Dalko]

(...)

The Agent was interesting to use because I really don't see D2 for that type of knife, certainly not at ~60 HRC so the Agent provides a differing opinion. I didn't see anything here that would change my mind however.

(...)

Plus I really don't like that kind of work with those types of steels because there is no warning to failure. I broke the tip of the H1 digging in woods and it is much thicker, but again stainless and similar steels have little deformation before fracture at ~60 HRC. They are near perfectly rigid and then they break.

If you are going to use D2 like that then P.J. Turner runs it well. He leaves it fairly soft to get the impact toughness up, so you can hammer on and with it.

(...)

-Cliff

Cliff,

I don't understand why you said you would lower the D2's HRC for heavy work because D2 is at its toughest state @ 60HRC accordingly to this Crucible page:

http://www.crucibleservice.com/datash/ACFC3C.pdf?CFID=175093&CFTOKEN=95655991

See the upper right corner chart on page 2 ----> Tempering temp = 500°F ----> 60 HRC ----> toughness = 23 ft-lbs

Thanks for your help.

 

[T. Erdelyi]

STEEL Carbon Chromium Cobalt Copper Manganese Molybdenum Nickel

D-2 1.40-1.60, 11.00-13.00, - - 0.60 , 0.70-1.20, 0.30

VG-10 0.95-1.05, 14.50-15.50, 1.30-1.50, — 0.50, 0.90-1.20 , —

Now VG-10 sems to be as brittle or even a little more brittle than D-2 what is it that makes them such an unforgiving steel?

 

[brownshoe]

I have a Queen toothpick in D2. For all I've heard about D2 being brittle the Queen treatment doesn't appear to make it brittle. My 4" thin queen toothpick has a very "springy" blade with no edge chipping at all, and it's at least as hard to sharpen as benchmade ATS34.

 

[knifetester]

what is it that makes them such an unforgiving steel?

Chromium.
Perhaps the Moly which makes it possible for them to be air hardened.

But I am not a metalurgist.

While stainless steels are brittle compared to plain carbon steels, spring steels and most tool steels, they are very strong. They resist deformation well. Then again, since strength is also a function of hardness, so will simpler steels when hardened to a high hardness, they simply loose some of their toughness.

Stainless steels often have higher wear resistance than carbon steels, they are more highly alloyed, and the chromium forms carbides itself.

However, stainless steels are often used because they stain less then carbons steels and that is what sells. It is also required in some industries, and is suited in marine use better.

 

[Cliff Stamp]

[impact tests]

...D2 is at its toughest state @ 60HRC

I have used Turners D2 at the lower hardness and the toughness is very high. In regards to impacts, I used it as a baton to drive other knives through the roof of a car, hard enough to knock chips out of the spine of a 1095 knife from Ontario and according to Kevin McClung, hard enough to break his differentially tempered O1 blade
[*], and the D2 blade was still unharmed and used extensively for an extended period.

[*]That was nonsense by McClung, that wasn't the reason his blade later broke, I just think it is funny that he actually stated publically that his O1 was more brittle than full hardened D2 and his fans accepted it as reasonable that statement alone is enough to completely write off his heat treatment.

I have a Queen toothpick in D2. For all I've heard about D2 being brittle the Queen treatment doesn't appear to make it brittle. My 4" thin queen toothpick has a very "springy" blade with no edge chipping at all, and it's at least as hard to sharpen as benchmade ATS34.

Thin blades will have a lot of "spring" because they experience little deformation under a given radius of curvature. This is why you can bend full hard M2 HSS blades insane arc's and they don't crack. The blade is so thin that it doesn't need to deform in order to make that bend. Phil Wilson can bend his 59 HRC S90V blades to 90 degrees and they don't crack. This doesn't mean the steel is actually flexible, due to the cross section it doesn't need to be.

-Cliff

 

[wolfmann601]

In english please!!!

Is D2 the toughest @ 60 HRC or is is toughest at some other HRC??

I thought most makers who utilize D2 swear by 60???

 

[Blop]

Would you like to get a D2 blade at 57HRC?

Between 59 and 61 seems to be the best ballance. You don´t get much more at lower hardness but the matrix isn´t hard enough to hold all the carbides.

 

[Cliff Stamp]

In english please!!!

Sorry, I am a Newfie, you are lucky you can read it at all, just stop by and try to talk to us in person.

Is D2 the toughest @ 60 HRC or is is toughest at some other HRC??

The charpy value is highest at 60 HRC, however the ductility is higher at lower hardness values. At 56-58 where P.J. runs it, it is quite resistant to fracture. Swamp Rat does a pretty solid job on thiers as well and they are running it harder and it still takes an impressive pounding as noted in the above.

I thought most makers who utilize D2 swear by 60???

No, some use 58 HRC because of grain refinement and wear resistance and some go up to 62 for hardness and edge retention based on resistance to rolling, there are two basic tempers, one high and one low.

A lot of people use 60 HRC regardless of the steel because it is the "magic" number for knife steels. In most cases other choices are more optimal, it depends on the steel and what you want from it.

Would you like to get a D2 blade at 57HRC?

That is where Turner runs the Uluchet.

...the matrix isn´t hard enough to hold all the carbides.

Not the case from what I have seen with it at that hardness, nor what I have read from others who have used it, no large edge tear outs.

-Cliff

 

[Dalko]

I don't understand... How can the D2's Charpy values be the highest at 60HRC if D2 is tougher at lower HRC?

Is it the same case with A2? A2's Charpy values indicate it is the toughest at 60HRC, do they represent reality?

 

[Gossman Knives]

Texas Knifemakers Supply heat and cryo treats my D2 blades at 58rc. That is their standard hardness level. They will take it higher if you request it. I have found that the treatment TKS does gives me exceptional results in the area of edge holding. I have not made any knives in the large chopper catagory with D2 so I do not know how they perform on that level. I use 5160 for those and I'm going to start using A2 also. The feedback from my customers who bought my D2 3" to 4 1/2" knives, has been nothing but positive.
Scott

 

[Cliff Stamp]

I don't understand... How can the D2's Charpy values be the highest at 60HRC if D2 is tougher at lower HRC?

Charpy values measure strength and resistance to fracture at the same time. This is why they drop with lowering of HRC values. It isn't that the steel tends to facture easier, however the strength is lower so it bends easier when the hammer hits it.

Charpy values are a good place to start from, but you also want to look at the steels in use, try them out for a few HRC values and see where the performance goes. This is one of the reasons that you should ask a maker what testing he has done and what HRC they have looked at.

Is it the same case with A2? A2's Charpy values indicate it is the toughest at 60HRC, do they represent reality?

I have tried it at the lower values and the toughenss and flexibility isn't there. Busse used to run it pretty hard and they have high standards so it would seem sensible to me. I would not use A2 for a heavy knife anyway, get A8 or better. The toughness difference between Missions A2 and Johannings A8 is extreme.

-Cliff

 

[STR]

Not to sound like a smart a$$ Cliff, but of course the knife tip of that D2 Agent broke off when you tried to carve a bowl with it and pry out a chip of wood. For one thing it is D2 tool steel known for being brittle, and for another it is the "Agent" model. I don't think Bob had in mind carving bowls or flicking out chips of wood with that particular model when he designed it Cliff. He probably had more in mind concealed carry for back up as a tactical knife for an on duty police officer or undercover 'agent'.

On the same note, you can't tell me that you didn't know that tip was going to break off or at least suspect that it would before hand in that particular test using a D2 knife blade. You have had more than enough experience to know ahead of time what D2 was and was not capable of doing. Frankly my friend, I'm surprised that you are surprised it snapped. With all due respect. Sometimes I think it looks like you just like destroying otherwise good knives.

Not that you are alone I guess there are a good many folks that appreciate your ruthlessness. But to me that was a no brainer. I could have told you in advance the outcome of that test before you ruined that knife.

That was the wrong test for this steel and this knife in my opinion Cliff.

 

[Gossman Knives]

Not to sound like a smart a$$ Cliff, but of course the knife tip of that D2 Agent broke off when you tried to carve a bowl with it and pry out a chip of wood. For one thing it is D2 tool steel known for being brittle, and for another it is the "Agent" model. I don't think Bob had in mind carving bowls or flicking out chips of wood with that particular model when he designed it Cliff. He probably had more in mind concealed carry for back up as a tactical knife for an on duty police officer or undercover 'agent'.

On the same note, you can't tell me that you didn't know that tip was going to break off or at least suspect that it would before hand in that particular test using a D2 knife blade. You have had more than enough experience to know ahead of time what D2 was and was not capable of doing. Frankly my friend, I'm surprised that you are surprised it snapped. With all due respect. Sometimes I think it looks like you just like destroying otherwise good knives.

Not that you are alone I guess there are a good many folks that appreciate your ruthlessness. But to me that was a no brainer. I could have told you in advance the outcome of that test before you ruined that knife.

That was the wrong test for this steel and this knife in my opinion Cliff.

Not only what you said, but what's the purpose of ALL these so called tests. Bob Dozier been around long enough to know how to make a good knife. Testing his knives IMO is unnesscessary. How many users are really going to use a knife to the extreme of some of these tests.
Scott

 

[brownshoe]

I don't always agree with cliff or his testing methods, but i like his testing of custom knives. It's intellectually stimulating. It shows how the myth/legend works in the real world. It also can be high entertainment as in his test of the pronghorn. It's his money...he can spend it whatever way he wants.

Dozier makes a variety of knives in a variety of methods. I don't understand why "Testing (Dozier's knives) IMO is unnesscessary".

Prying a little wood while making a bowl is not too stringent of a test for a knife that may have "tatical" purposes. Is the agent strickly a slicer? I doubt it. Doesn't look like one. Would you expect this knife to be used in prying...possibly, but the test that broke the tip was not one of tip strength. The tip broke during an activity where no special stress was being place on it.