Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
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, over 600 pages, 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. Note than when the knives were drawn from the wood, care was taken not to induce any lateral strain on the blades
Heavy wood cutting :
I did some cuts into various woods, and woods wrapped with fabric to see if I would break the knives with high force swings. This did nothing to any of the blades. I then did some heavy whittling on some very hard and knotty wood to try and break the knives. Outside of jamming the knife into the wood and pressing hard sideways which would break the knives easily, nothing could be done to induce any damage to the blades. The knives were then used to split several small pieces of pine and spruce . The blades make poor wedges as they are so thin they induce no splitting action, and are so short you can only work on small pieces of wood. But again no harm came to the blades. I was using another piece of wood as a mallet. This was all done with the stock edges at a high polish.
Bone :
I started out with some light bones, chicken and turkey. All of the blade could do sloppy press cuts through the joints (cut through the bone not the cartridge), with no damage. As a surprise I found some seal parts I had put away last winter for such use. The blades cut through the flippers using a hatchet handle as a mallet. It took on average 10-15 hits to pound them through the bone 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 [I had resharpened it for some whittling].
Upon a closer inspection, the D2 blade had suffered a bend in the tip. This was surprising as I would have expected this from the AUS-8A blade as it is softer. However 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 much thicker, ~ 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, it shows how much of an effect that steel thickness has on the ability to bend and not break.
Metal cutting :
I started out hammering the blades 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. I started out very light taking 125 cuts to go through the hanger with the D2 blade. With every cut I could go faster with no damage to the blades. After producing a small pile of metal bits I switched to nails which are much harder steel. Starting with a two inch nail it was cut with 69 hits using the VG-10 knife.
Then I switched to a two and half inch nail and cut it in 70 hits, and finally a three and a half inch nail and cut it with less than 30 hits. With each cut I was again getting faster and none of the blades had any problem, with the exception of the VG-10 blade which got damaged on the three and a half inch nail when I used a sloppy hit and snapped more than the full edge away (break was 0.022" thick at back). However I cut two more pieces off with no damage.
In short I could not tell the blades apart on the metal. While there are difference in hardness, ductility and impact toughness in the three steels, the damage was much more sensitive to technique. If the hits were made straight down on the spine, and the knife was pressed firmly into the metal, even very thick nails could be cut without difficult. I was curious if I could cut a six inch spike in this manner but had none on hand.
I then did more dynamic cutting. Hanging the coat hanger from some strapping, I did twelve cuts into it 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 as tightly as I could, 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 I was resisting so much, that I had to stop after every few hits or the knife would have been knocked out of my hand. Each blade was subjected to twelve hits on the spine and on the flats. No damage was done to any of the blades.
Concrete block stabbing :
The blades were dropped onto a concrete block, tip first, from six feet. The AUS-8A blade suffered a tip bend, about a half a mm deep, bent close to a full 90 degrees. The VG-10 and D2 blade were not effected. 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 mm deflection running about two mm 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 mm 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 mm and three mm 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. In short :
A8 -> bent on drop
VG -> six drops no bend
D2 -> bent after six drops
D2 -> snapped on first stab
VG -> bent after six stabs, broke on the next
A8 -> bent after 12 stabs, 18 more to break
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 impacts :
The blades were struck with a 600 g mild steel bar on the spine and on the flat 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. I was slightly curious to see how many hits they could take, but the impacts were doing a number on my hand and my friend didn't have the confidence in my then shaky hand for him to hold the blade.
Prying :
The blades were viced and broken. They all broke very easy using just wrist torque. The VG-10 blade literally exploded in four pieces. The AUS-8A and D2 one 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. I then locked just the edge in the vice and broke a piece out of the remaining blade length. Again the VG-10 blade shattered, the AUS-8A one broke cleanly, and the D2 one bent much further and was now actually difficult to break. It also lost a much smaller piece than the other knives.
Ref :
Rope cutting : http://www.bladeforums.com/forums/showthread.php?s=&threadid=241331
Cardboard slicing : http://www.bladeforums.com/forums/showthread.php?s=&threadid=236308
Corrosion tests : http://www.bladeforums.com/forums/showthread.php?s=&threadid=242736
-Cliff
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, over 600 pages, 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. Note than when the knives were drawn from the wood, care was taken not to induce any lateral strain on the blades
Heavy wood cutting :
I did some cuts into various woods, and woods wrapped with fabric to see if I would break the knives with high force swings. This did nothing to any of the blades. I then did some heavy whittling on some very hard and knotty wood to try and break the knives. Outside of jamming the knife into the wood and pressing hard sideways which would break the knives easily, nothing could be done to induce any damage to the blades. The knives were then used to split several small pieces of pine and spruce . The blades make poor wedges as they are so thin they induce no splitting action, and are so short you can only work on small pieces of wood. But again no harm came to the blades. I was using another piece of wood as a mallet. This was all done with the stock edges at a high polish.
Bone :
I started out with some light bones, chicken and turkey. All of the blade could do sloppy press cuts through the joints (cut through the bone not the cartridge), with no damage. As a surprise I found some seal parts I had put away last winter for such use. The blades cut through the flippers using a hatchet handle as a mallet. It took on average 10-15 hits to pound them through the bone 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 [I had resharpened it for some whittling].
Upon a closer inspection, the D2 blade had suffered a bend in the tip. This was surprising as I would have expected this from the AUS-8A blade as it is softer. However 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 much thicker, ~ 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, it shows how much of an effect that steel thickness has on the ability to bend and not break.
Metal cutting :
I started out hammering the blades 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. I started out very light taking 125 cuts to go through the hanger with the D2 blade. With every cut I could go faster with no damage to the blades. After producing a small pile of metal bits I switched to nails which are much harder steel. Starting with a two inch nail it was cut with 69 hits using the VG-10 knife.
Then I switched to a two and half inch nail and cut it in 70 hits, and finally a three and a half inch nail and cut it with less than 30 hits. With each cut I was again getting faster and none of the blades had any problem, with the exception of the VG-10 blade which got damaged on the three and a half inch nail when I used a sloppy hit and snapped more than the full edge away (break was 0.022" thick at back). However I cut two more pieces off with no damage.
In short I could not tell the blades apart on the metal. While there are difference in hardness, ductility and impact toughness in the three steels, the damage was much more sensitive to technique. If the hits were made straight down on the spine, and the knife was pressed firmly into the metal, even very thick nails could be cut without difficult. I was curious if I could cut a six inch spike in this manner but had none on hand.
I then did more dynamic cutting. Hanging the coat hanger from some strapping, I did twelve cuts into it 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 as tightly as I could, 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 I was resisting so much, that I had to stop after every few hits or the knife would have been knocked out of my hand. Each blade was subjected to twelve hits on the spine and on the flats. No damage was done to any of the blades.
Concrete block stabbing :
The blades were dropped onto a concrete block, tip first, from six feet. The AUS-8A blade suffered a tip bend, about a half a mm deep, bent close to a full 90 degrees. The VG-10 and D2 blade were not effected. 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 mm deflection running about two mm 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 mm 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 mm and three mm 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. In short :
A8 -> bent on drop
VG -> six drops no bend
D2 -> bent after six drops
D2 -> snapped on first stab
VG -> bent after six stabs, broke on the next
A8 -> bent after 12 stabs, 18 more to break
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 impacts :
The blades were struck with a 600 g mild steel bar on the spine and on the flat 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. I was slightly curious to see how many hits they could take, but the impacts were doing a number on my hand and my friend didn't have the confidence in my then shaky hand for him to hold the blade.
Prying :
The blades were viced and broken. They all broke very easy using just wrist torque. The VG-10 blade literally exploded in four pieces. The AUS-8A and D2 one 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. I then locked just the edge in the vice and broke a piece out of the remaining blade length. Again the VG-10 blade shattered, the AUS-8A one broke cleanly, and the D2 one bent much further and was now actually difficult to break. It also lost a much smaller piece than the other knives.
Ref :
Rope cutting : http://www.bladeforums.com/forums/showthread.php?s=&threadid=241331
Cardboard slicing : http://www.bladeforums.com/forums/showthread.php?s=&threadid=236308
Corrosion tests : http://www.bladeforums.com/forums/showthread.php?s=&threadid=242736
-Cliff
