Deerhunters in AUS-8A, VG-10 and D2 from A. G. Russell


Specifications

The Deerhunter is made in Japan for A. G. Russell [ref].

The overall length is 8.25 inches, with a four inch drop point blade ground from 0.080" thick stock. It is offered in three steels; AUS-8A at 57-59 RC, VG-10 at 60-62 RC, and D2 at 60-62 RC. The knife is neutral in balance and weighs just 3.4 ounces (about 60 grams).

These knives were donated by A. G. Russell, intended for a durability comparison. The scope of work was widened due to curiosity about other aspects of performance. Another Deerhunter in AUS-8A was reviewed several years ago [ref].

Initial sharpness and cutting ability

With the edge geometry determined, the initial sharpness was measured for the three Deerhunters and some cutting done on 3/8" manilla hemp rope to illustrate the cutting ability :

Edge geometry and initial sharpness and cutting ability of the Deerhunters.
Steel Edge Thread Poly Hemp
thickness angle push slice
inches degrees grams cm lbs
AUS-8A 0.020-0.025 13-14  60 +/- 21 0.38 +/- 0.13 14-18 13-15
D2 0.012-0.020 12-13 165 +/- 62 1.48 +/- 0.27 14-28 19-21
VG-10 0.018-0.022 15-17 140 +/- 34 0.80 +/- 0.31 14-24 13-15

It is obvious from the sharpness testing that the blades are all very sharp there is also a large variance in the behavior, about 30% for the thread cutting, showing the sharpness was not consistent. While the blades in general all shaved and cut light paper well, the difference in sharpness along the edge was readily noticable as in some spots they could shave freehanging hair and do straight 90 degree push cuts down into newsprint whereas in other places they could not.

Checking the edges under light, spots of reflection could be noticed on all blades, worse for the D2 and minimal for the AUS-8A blade. Under magnification [x20] the edge of the VG-10 blade was smooth, however had 50 micron deep chips with a frequency of one chip per 5 millimeters . The AUS-8A edge was rough, chips of 25 microns deep were present along the entire edge, and larger chips several times more frequent than on the VG-10 blade. The D2 edge was smooth under magnification, no chips.

Note that while the hemp cutting was strong for all blades, the influence of the sharpness difference was significant. In particular the D2 blade showed a large lack of aggression on a slice which is directly correlated to its performance on the poly. The range for the push cut on hemp is so large as it spans the performance from the choil to the tip, the tip being able to much more of a rocking cut is much more efficient and is thus about 14 lbs with all blades.

NOTE : the characteristics shown in the above don't indicate inherent behaviors of the steels, they are just due to variablity in sharpening.

A quick and dirty cardboard comparison

As a simple check on cutting ability and edge retention, the Deerhunters were used to cut 1/4" double ridged cardboard slicing through the ridges using the entire blade length. The goal was to cut with each blade until they failed to make clean cuts and use this as a measure of edge retention, the edges could then be examined for wear under magnification and tested for sharpness on thread and 1/4" poly using standard methods.

Each Deerhunter cut all available cardboard, ~600 feet total and they could not be differentiated during the cutting by feel. After the cutting as a check for sharpness the knife were cut into a piece of cardboard and would start a cut with less than a pound of force but needed ~25 lbs to complete a cut. Thus sharpness had a very small effect on the cutting ability, specifically edge degradation of 50% would change the cutting ability by just ~4 percent - which means huge changes in edge retention would be necessary to notice a difference in feel.

As well, in reflection, slicing in general is a poor check for sharpness as it "smears" out the cut so the effect of blunt spots can be hidden. A blade can be far blunter and still able to slice a material well when it is failing to do a push cut. The cardboard cutting should have been push cuts on a restricted section of the blades, which would have induced blunting at a much faster rate, and allowed a a quick and easy comparison of before and after sharpness as much of the blade would still be at full sharpness.

Inspecting the blades under magnification, the edge AUS-8A blade had had suffered the most extensive blunting, missing pieces of the edge twice as deep as the other Deerhunters. The edge had 2.5 millimeter chips, with worn patches up to one centimeter long [x20 mag] and as much or more in total amount of wear. The VG-10 and D2 Deerhunter were very close in appearance under magnification, it would be difficult to judge which was more worn, but the D2 blade would probably be given the nod.

The blades were then stropped, five passes per side on CrO. The AUS-8 blade was back to hair shaving ability and was now sharper than the other two knives. Under magnification though the more extensive edge damage was still present, the edge was just more responsive to alignment as it is softer. When the edges were restored fully using SiC sandpaper, the AUS-8A blade took 30 passes per side, and the D2 and VG-10 one only ten per side.

Note that the harder and more wear resistant blades take less blunting in the cutting and take less effort to restore to full sharpness as the blunting isn't as extensive. The softer blade was however more responsive to the stropping as the edge will be more readily deformed. Geometry was also shown to be much more key in determining the cutting ability of a knife when cutting thick and binding materials than the actual sharpness of the edge.

Stock cutting

The Deerhunters were honed recutting the edges with fifteen micron SiC sandpaper, refined five micron SiC paper, and finish honed on CrO loaded leather. No significant difference was noted in the initial sharpness of the blades of the cutting ability with the freshly honed edges. Through six cuts on once inch basswood with a two inch slice, the Deerhunter took 7 +/- 2 slices to make a point. Using rocking press cuts through 3/8" hemp, the blades took 32-34 lbs near the base, and 16-17 lbs through the tip.

UPDATE : the results on the hardwood were a little too uncertain, usually this is repeated until the variance is about one cut. This was intended here as well but was forgotten until about half way through the durability testing described further below.

An extended and detailed comparison on hemp (Manila)

The Deerhunters were used on 3/8 inch hemp, sliced on a two inch draw. The sharpness was tested periodically using quarter inch poly held under 1000 g of tension and cut on a draw with the blade length needed to make a cut taken as a measure of the sharpness. The amount of force needed to cut the hemp was also noted periodically during the cutting, but it is a much more coarse measurement of sharpness as it depends strongly on the geometry. Three rounds of cutting was performed with each blade with 254 cuts for each blade in each round, 2286 cuts in all.

The blades were sharpened before each session, starting with a profiling using SiC sandpaper to set the bevels, working up to 400 grit. The final sharpening was on a 600 grit DMT rod set at 22 degrees [just because it is an available fixed angle]. The edges were formed with 15 alternating strokes per side to insure that the edge was fully composed of the 600 finish, only about 5 per side are really necessary. The edge was stropped on chalk non abrasive paste to clean up the grit and steel debris. All edges were checked under magnification for uniformity of finish.

cutting ability

With an identical edge finish, and very similar edge geometry, no significant difference was noted in the initial performance of the Deerhunters on the hemp rope, all were very aggressive and sliced the cord well. The following table shows the amount of force used on the cuts periodically measured throughout the cutting :

cutting ability of Deerhunters on hemp
Hemp cuts AUS-8A VG-10 D2
222.0 +/- 1.1 25.5 +/- 1.5 22.5 +/- 1.5
625.0 +/- 1.5 25.5 +/- 3.8 22.0 +/- 2.3
1426.0 +/- 2.7 26.0 +/- 0.8 21.5 +/- 1.1
3028.0 +/- 1.9 25.0 +/- 0.8 22.0 +/- 1.5
6231.0 +/- 1.1 29.0 +/- 0.8 25.0 +/- 0.8
12630.5 +/- 0.8 29.0 +/- 0.4 26.0 +/- 0.8
25430.5 +/- 1.9 28.5 +/- 1.4 26.5 +/- 1.4

The Deerhunters start off requiring slightly more than 20 lbs with all blades feeling similar initially. As the cutting progresses the D2 blade retains more aggression than the VG-10 one, and the AUS-8A is clearly last. However because the hemp cutting is so dependent on geometry, it is difficult to separate out the effect of blunting as it is only a pound or two in the difference among the blades.

edge retention

To focus on sharpness, the blades were periodically used to make cuts on quarter inch poly as described in the above. Since this cutting is not as geometry dependent as the hemp cutting, the effect of the sharpness is magnified and thus small difference in performance of that aspect are readily observed.

edge retention on hemp as shown by performance on quarter inch poly
Hemp cuts AUS-8A VG-10 D2
0 0.8 +/- 0.0 0.9 +/- 0.1 0.8 +/- 0.1
2 1.0 +/- 0.1 0.8 +/- 0.2 1.0 +/- 0.1
6 1.2 +/- 0.1 1.1 +/- 0.2 1.1 +/- 0.1
14 1.6 +/- 0.2 1.4 +/- 0.1 1.3 +/- 0.1
30 2.1 +/- 0.1 1.8 +/- 0.2 1.6 +/- 0.2
62 3.0 +/- 0.3 2.5 +/- 0.1 2.0 +/- 0.1
126 4.0 +/- 0.5 3.5 +/- 0.4 2.6 +/- 0.1
254 5.6 +/- 0.2 4.5 +/- 0.3 3.5 +/- 0.2

Again all the blades cut equally well initially, as the cutting progresses the VG-10 Deerhunter retains more aggression than the AUS-8A version, and the D2 one more aggression than the VG-10 blade. For the first few cuts this difference is masked by the variance in the performance, but as the cutting continues the separation of the performance becomes clearly evident. As a much more readily digestible form :

The graph shows the VG-10 blade is consistently ahead of the AUS-8 one, it takes about 50% more material to induce a similar amount of blunting on the VG-10 Deerhunter. The D2 version is further ahead by about 100% over the VG-10 blade. The separation between the D2 and VG-10 blades is great enough that there is a large difference felt in the cutting, with the D2 one remaining more aggressive on the rope for far longer, less slippage and less force was required.

As an importance detail, edge retention comparisons are complicated because blunting is not a linear process. This means that a different perspective is realized if the blades are compared at a certain blunting point (sharpness reduced to 50% for example) rather than how after a specific amount of material has been cut (two hundred cuts of rope for example). Both comparisons would have the same ranking order, however the distances between the ranks would be far greater for the first method.

As a specific example, looking at the sharpness after the after the 254 pieces of hemp rope were cut :

alternate edge retention on hemp rankings
Model Hardness Ranking
D260/62100
VG60/6276 +/- 7
A857/5962 +/- 5

However such a ranking makes little sense because knives are sharpened after reaching a certain "bluntness" thus what is most meaningful is how much material needs to be cut for a knife to reach a certain state of edge degradation. This makes matters complicated because the rankings are then dependent on the chosen stopping point. In general, the lower the tolerance for sharpness (how blunt the knife will go before sharpening) the greater the edge retention advantage of the superior steels.

As a side note, to be optimal, a number of blades of each type should be tested, three of each would be a minimal set. As well it would informative to have RC tests on the blades insuring that they fell in the required ranges. Note as well, that while edge retention on hemp rope can be extended to a lot of other materials (as well as a general inference on cutting ability), some other materials, such as chopping wood place very different requirements on a knife.

ease of sharpening

Ease of sharpening is one of the biggest over hyped and largest knife myths on the market. Ease of sharpening is influenced mainly by how well the steel choice and knife geometry suits the class of knife. Essentially the steel type should be one that prevents gross edge damage (fracture, deformation or corrosion) and the geometry one that minimizes the edge profile in width.

After the above hemp cutting, the Deerhunters could be taken back to 100% sharpness from the final stage which was about 25% of optimal, with a few strokes on a v-rod setup. Even when blades are very blunted, the sharpening time isn't significant. On runs with other blades where the performance was down to less than 10% of optimal after much rope cutting, the sharpening required was still just a few passes on a ceramic or diamond rod.

In general, unless the edge is damaged, the amount of material that needs to be removed from a very blunt blade to restore it to a very sharp one only microns deep even for a full edge reset, which is often a waste, machinability is generally only a concern for a maker.

Corrosion resistance

The Deerhunters were sharpened including an edge reset, and finished with a DMT 600 grit rod set at 22 degrees. Again no significant difference in sharpness was noted among the blades testing the edge on quarter inch poly. The knives were dipped in lemon juice to a depth of a quarter inch from the edge. After a two hour soak the AUS-8A and VG-10 blade were not visibly effected and had no sign of corrosion and the edge bevel grinds lines were still clear under the magnification (20x). The D2 blade had a distinct patina in all the contact area and parts of the edge bevel were solid black with oxidation (~one cm long sections). Under magnification, the grind lines were blurred out, and the edge bevel showed frequent large irregularities where corrosion had removed significant amounts of metal (~10x greater than the micro teeth left by the DMT rod).

However when tested for sharpness on the poly, the blades showed similar performance and no significant blunting. Based on previous experience with corrosion soaking, this can be misleading as the edge can be significantly weakened by rust but still appear sharp. To test the full effect of corrosion the blades were used to cut sixteen pieces of hemp. The D2 Deerhunter was aggressive but much harder to pull through the hemp. The VG-10 and AUS-A8 blades showed similar aggression, but cut with much less force. The sharpness was again tested on quarter inch poly. Compared to the above hemp cutting, the VG-10 and AUS-8A Deerhunters showed a similar loss in sharpness and thus were not significantly effected by the lemon juice. However the D2 Deerhunter wore down much faster in use after being exposed to lemon juice and now blunted the fastest out of all three steels. It was now blunting twice as fast as the VG-10 blade, whereas it was holding its edge for twice as long without any corrosive effects.

Details :

effect of corrosion on sharpness and edge retention

Model Initial After two hours After 16 hemp cuts
soaking no soaking
D2 1.10 +/- 0.16 1.31 +/- 0.18 2.30 +/- 0.24 1.30 +/- 0.08
VG1.14 +/- 0.22 1.20 +/- 0.10 1.66 +/- 0.17 1.35 +/- 0.09
AUS-8A1.10 +/- 0.09 1.13 +/- 0.19 1.70 +/- 0.28 1.55 +/- 0.15

After the cutting the blades were resharpened. The effect of corrosion can readily be noticed during the honing. The D2 Deerhunter appeared to clean up without problems, but refused to take a clean finish, the edge broke away. Checking under magnification, holes can be seen as pits are exposed in the edge. All that corroded steel had to be removed before the edge could be formed crisp and clean. In comparison the VG-10 and AUS-8A blade were free of such problems and sharpened very quickly.

As a side note, other D2 blades have also shown low corrosion resistance. Specifically a custom made D2 utility knife from Mel Sorg, actually corroded during in the shipping, taking a light surface coat of rust, and pitted deeply when exposed to salt water. In general though D2 handles surface rust a lot better than steels like L6 which can take a visible patina in minutes even cutting up an apple. Heat treating also make a difference, but regardless D2 will tend to rust rather easily compared to the stainless cutlery steels.

UPDATE : getting particular, the above comparison between the blades cutting the rope after being soaked and while not being soaked, one was after 16 and the other 14 cuts. This was not intentional, the 16 cuts were supposed to be 14. However this difference isn't significant, certainly not enough to explain the huge difference in the behavior of the D2 Deerhunter. The reason for the quicker blunting can be directly observed under magnification to be the extensive corrosion as noted.

Durability

After the cutting the Deerhunters were used for a variety of very hard work, up to and exceeding the point of gross failure.

heavy tip work

The knives were stabbed into a phone book (reverse grip for maximum stress on the tip), a total of six times each. The penetration was high, the AUS-8A version averaged 661 +/- 7 pages, the VG-10 one 672 +/- 40, and the D2 one 714 +/- 22. This is especially impressive if the low weight of the blades is considered, showing a very efficient point profile. In comparison the Howling Rat from Swamp Rat Knives averages 627 +/- 8 pages at a weight of 185 grams, more than three times the weight of the Deerhunters. The Deerhunters were then stabbed into a piece of pressure treated 4x4, again in reverse grip. A total of six stabs were made with each blade giving on average over an inch of penetration. No damage was done to either blade. However note that when the knives were drawn from the wood, care was taken not to induce any lateral strain on the blades

heavy wood cutting

Hacks were made at various wood, high impact swings with full force, and and woods wrapped with fabric. Very heavy whittling on some very hard and knotty wood was then performed. The Deerhunters were then used to split several small pieces of pine and spruce using another piece of wood as a mallet, using very heavy swings. The blades make poor splitters, as they are short and so thin they wedge readily. blades. None of this had any effect on the blade.

bone

On some light bones, chicken and turkey, all Deerhunters could do sloppy press cuts through the bone of the joints with no damage. They also were used to chisel cut through various seal parts, using a hatchet handle for a mallet. It took on average 10-15 hits to pound the knives through the bone in the flippers which was about one sixteenth of an inch thick, and about half an inch wide at the largest. The blades were then used to cut through several sections of the spine. Lastly they were stabbed into the skull at various angles with full force, so much so that they would get stuck into the board underneath it. None of the edges took any damage, and were still sharp enough to catch on a thumbnail and cut the flesh. In retrospect this comparison was a little sloppy as the AUS-8A and D2 blade had 0.1 to 0.3 mm wide 600 DMT 22 degree micro bevels from the earlier rope cutting , and the VG-10 one had a full 14-16 degree polished edge as it was used for some test whittling.

Upon closer inspection, the D2 blade had suffered a bend in the tip. However this was due to geometry, the tip on the D2 blade was significantly finer than on the other two knives. About one quarter inch back from the tip, which was the length of the bend (deflected just a degree or two, very slight), the D2 blade was 0.018" thick, however the VG-10 and AUS-8A blade were ~0.028". Thus the stainless blades were 50% thicker in the tip which would make them more than twice as strong in respect to resisting lateral loads. Thus the difference in thickness was the deciding factor and not the steel. It is interesting that the D2 blade was able to take a bend and not break given the high hardness, showing how much of an effect that steel thickness has on the ability to bend and not break.

metal

The Deerhunters were first used to chisel through a coat hanger. The cutting was done using the head of one hammer for a cutting board, and a 22 oz framing hammer for a mallet. It started out light taking 125 cuts to go through the hanger with the D2 blade. With every cut made more force was used. After producing a small pile of metal bits, nails were used as further cutting stock, much harder steel than a coat hanger.

The first cut was on a two inch nail, sectioned in 69 hits using the VG-10 blade. A two and half inch nail was cut in 70 hits, and then a three and a half inch nail was cut in less than 30 hits. The blades had no problems, except the VG-10 blade got damaged on the three and a half inch nail when a sloppy hit which snapped the blade sideways broke the edge away to 0.022" thickness (more than the full edge). Two more sections of the nail were cut with the VG-10 Deerhunter with no damage, similar force was used however with more careful taken to prevent lateral loads.

For some dynamic cutting, a free hanging coat hanger was hacked into twelve times with each knife. The swings were at full speed and cut deeply into the coat hanger. The AUS-8A knife was visibly rolled in a few places, the D2 and VG-10 blade wasn't significantly effected, no visible rolling or chipping.

high impacts

Holding the blades tightly, they were subjected to impacts from a three foot length of 2x2 . The impacts were that high (much more so than would be needed to split the wood as noted in the above for example), and the blades gripped so forcefully, that rests needed to be taken every few hits or the blades would have been knocked out of hand. Each blade took twelve hits on the spine and on the flats with no damage.

concrete block stabbing

The blades were dropped tip first onto a concrete block from six feet. The AUS-8A blade immediately suffered a tip bend, about a half a millimeter deep, bent close to a full 90 degrees. The VG-10 and D2 blade were not effected from the initial drop. After six drops the VG-10 blade was still unaffected, the AUS-8A blade had a bit more of a tip bend, and the D2 tip regained its tip bend from the bone cutting but now more severe, a half a millimeter of deflection running about two millimeters deep.

The blades were then stabbed into the block at full force until the tips broke. The impacts were taking large pieces out of the block, several millimeters deep. The D2 blade broke on the first impact, not surprising considering the bent tip changed the impaction force into a lateral prying strain. After six impacts the VG-10 tip had deflected by about a millimeter and was three millimeters deep. The tip then snapped on the next hit. The AUS-8A blade took another six hits before it took a tip bend which was 1/16" off normal and 1/8" deep. It took another 18 hits before it broke.

Note as described in the above, the D2 tip is much thinner than the VG-10 and AUS-8A tips. The stainless steel tips are 50% thicker so the tip on the D2 Deerhunter bending and then breaking so fast is not just reflective of the steel but rather the geometry.

really high energy impacts

The blades were struck with a 600 g mild steel bar on the spine and on the flats with the corner of the top of the bar aimed at impacting on the middle to edge of the knife on the flat for maximum effect. All blades took a dozen hits on the spine, none of them broke. However the VG-10 knife lost large pieces out of the spine with every other impact. These were up to 1/8" long and about 1/32" deep. The VG-10 blade broke on the first impact on the flat. The AUS-8A and D2 one took the full twelve hits without breaking. At this point the hammering was stopped due to difficulty in holding onto the blades, the repeated impacts are very jarring on the grip.

prying

The blades were viced and they all broke easily using wrist torque. The VG-10 blade literally exploded in four pieces. The AUS-8A and D2 Deerhunters snapped cleanly. The D2 blade bent the furthest, reaching 90 degrees before it broke, and it had the largest permanent bend in the remaining section of blade. Just the edge of the blades was then locked in the vice and the blades again leaned on until they fractured. Again the VG-10 blade shattered, the AUS-8A one broke cleanly, and the D2 one bent much further and was actually difficult to break. The D2 Deerhunter lost a much smaller piece out of the edge than the other knives.

sheath

The strength of the hanging steel clips was also examined, all three broke at about ~45 lbs, snapping through the back of the clip where it is thinnest.

overview

The VG-10 consistently fared the worse on the heavy tests, hammering, nail cutting and prying. This shows a lower impact toughness and ductility. It should be noted however that the effect of the work is cumulative. For example the bar strikes would have been influenced by the nail hammering, and the quick break of the VG-10 when hit on the flats flats would obviously be influenced by the fact that it had large pieces missing from the spine. The more brittle blades would break much faster as the testing went on not only because they would take damage easier, but the damage they took would make it more likely for further damage to be induced.

Just a quick comment on the overall durability, the above can not be readily extended to larger blades. The Deerhunters are very light, a large blade can easily be ten times as heavy. This means they will directly have this much more impact energy possible because of the much more powerful swings. But specific to the Deerhunters, they showed themselves of being capable of very heavy work, prying was the only real weak point. They are trivial to break under any lateral strain. However if you avoid this, and check to make sure that the point isn't ground really thin (like the D2 blade in the above), the overall durability is very high. Of course the thinner tip has advantages in many aspects so for a light utility or hunting knife you might prefer the thinner tip.

Overall

The Deerhunter is well known for its high cutting ability due to the thin blade stock, full flat grind and thin and acute edge, however it also showed to be very durable and capable of a wide range of tasks. The only significant weak point which limited the scope of work was the low lateral strength due to the thick blade stock, it can easily be broken when used to pry.

Comments and references

You can comment on this review by dropping me an email : cliffstamp[REMOVE]@cutleryscience.com or by posting in the following threads on Bladeforums :




Last updated : Mon Sep 8 09:36:41 NDT 2003
Originally written : Mon Jun 30 13:21:56 NDT 2003

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