Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Joe has some comments on it here :
http://www.bladeforums.com/forums/showthread.php?s=&threadid=235127
Initial lock testing :
1) White knuckle test. This can open lock backs and very frequently unlocks liner locks, I could open a Spyderco Military this way, after it had been adjusted at the factory for example. Niemi's lock actually needs the handle slabs to open for the lock to release so all that this does it reinforces the lock (this is of significant importance on several of the lock tests) .
2) Spine whack. Using both a light and whippy motion and a hard impact swing, the tip of the blade was struck against a piece of wood in order for the effects of sudden fast shocks and heavy impact loads to either induce impaction of the mating surfaces or have something just get jarred apart. None of this had any effect, I worked up to swinging the knife hard enough to dig 1/4"+ holes in cedar.
3) I took a 4 foot piece of cedar baseboard and reduced it to shavings. I then repeated it with a piece of hardwood baseboard, which had a lot of splintering, and general wood breakage, and thus increased the torque on the lock. I went as heavy as possible, quickly, to maximise the strain on the lock, with no care to eliminate torques. I also cut deeply and twisted to break the wood out, as well as jerked back to pop the blade free. No effect on the lock.
4) I put the point in a piece of 4x4 and twisted the grip trying to get the slabs to open. This wasn't possible, they are far too rigid. I then resorted to having a friend push on the 4x4 while holding the knife as tight as I could and all I could do was twist the knife out of my hand. This combination of twisting and vertical loads can easily causes most liner locks to disengage and even break. I broke the liner on a Buck/Strider doing this with far less effort.
5) With the blade tip in the wood (just inserted in a crack) I bent the knife until the handle was at 30 degrees off of perpendicular (the wood was giving somewhat so the angle includes that deformation as well), the blade now had a slight visible bend. The handle slabs did not open at all. Unloading the knife, the blade returned to straight and the lock was not effected. This was about the maximum I could bend the knife using just my wrist strength. Because of the thickness of the handle liners, they are too rigid to bend significantly.
In short, the above places it above any lock that I have seen so far in regards to both raw strength as well as security. Before I did anything harder I then did some cutting tests as the blade profile is actually quite interesting and offers quite high cutting performance. The blade has a primary hollow grind, which I would call hollow relief as it isn't "T" shaped hollow which can wedge tightly at the top of the grind. The primary edge profile is 0.028" thick and 0.083" wide which is less than 20 degrees included. On top of this there is a more obtuse secondary edge bevel just barely visible .
Stock cutting tests :
The blade could push cut 3/8" hemp at ~14 lbs near the base of the blade and ~22 lbs near the tip. The increase in force was just due to the tip being slightly blunter. It only took 6.2 (0.2) slices to point a one inch hardwood dowel. For reference, the Cold Steel Twistmaster took ~12 slices on the dowel, and ~40 lbs on the cord. The cutting performance is well above average.
Sharpening :
Before the stock tests, but after the above wood cutting, the blade would not shave any more so I stropped it on CrO, ten passes per side. The shaving edge returned and there was little evidence of a floppy burr. The knife was then used in the kitchen on ripe tomatoes and peppers which it handled fine. Clean cuts with no mashing. Works very well for that kind of use, more shortly. This stropping was repeated several times during the work with the blade, it restored the shaving finish each time.
General blade shape :
The blade looked odd at first, upswept, but it actually isn't. The point profile is traditional tanto, with the point inline with the spine. There is just a curve in the spine which makes the point appear to rise. This curvature makes the blade fit smoothly in the grip. The shape gives a lot of curvature near the tip which enhances slicing ability as well as rocking cuts. It works very well on vegetation in the kitchen for this reason, as well as the lack of a guard allows cuts full to the cutting board. In addition because the blade is sharpened fully back, no choil, it works well as a paring knife. It was also used to trim the fat from some chicken legs as well as do rocking cuts straight through the bone, no significant blunting was induced, let alone edge damage.
Handle :
The handle fills the hand well, and is decently secure, no slippage was noted. The inside of the inside S30V liners is a little square though and did cause some irritation with extended use. A guard would also be appreciated by some to enhance security on thrusts .
Flickability :
The lever that opens the lock (it engages when the knife is closed as well as open), takes 6-8 lbs to rotate. This isn't a huge amount of force, but it a lot more than a smooth liner lock. This isn't a lock that you are likely to flick open and close for entertainment. I did a short cycle of 250 opens and closes to see if any slack would develop and I had to stop every 50 times. That being said, I carried the knife for awhile and used it to cut anything regardless of how trivial, it quickly became second nature to open. I just popped it with my thumb while holding the knife steady in a sideways sort of pinch.
Heavy lock work :
I chopped a couple of sections of the hardwood baseboard in two. Using the Camp Tramp (Swart Rat knives), sitting down, just swinging from the elbow it chopped easily in 12-14 hits. Standing up, doing fully power swings, it would take 3-7, and the board would be falling apart under the impacts. The folder took 38-42 hits. It took as many because I was holding back on the grip and the hits were landing really sloppy. The penetration was very high for the impact energy. No effect on the lock.
The blade was loaded vertically with 869 in.lbs of torque (just a particular weight I had a hand). To put this in perspective, if you could lift a 8 lbs sledge hammer by the very end of the handle with one hand, you would be of above average strength - that is less than 300 in.lbs of torque. I attempted to apply more of a load but could not keep the blade in position. In any case, the amount of steel that you need to break to cause the lock to release is many times that of normal folders. The break strength would be insanely high .
The blade was loaded sideways to see if I could pop the handle apart enough to get the lock to release, here is where I made a mistake. I thought I was loading the blade with 250 in.lbs, as I approached the maximum the blade snapped cleanly in half. The blade didn't bend significantly before it broke, and it was perfectly straight after the snap. When I checked the lever arm again the maximum torque was 350 in.lbs. I would estimate it was 275 - 325 in.lbs when it broke.
[this cut short the cutting part of the review]
The lock was then examined to see how it would handle dirt in the mechanism. I took ash from the wood stove (which also is used as a dust pail in the basement) and pushed in into the lock from all directions once it was closed. The blade still engaged fully when the lever was thrown. I then jammed it full of ash and dirt again when it was open and then flipped the bar and closed it. No problem. I then repeated it a few times. Unlike many other locks this one has the mating surfaces fully engaged when both open and closed so they can't get contaminated. The only way for this to happen would be to open it in a really dirty situation so for the brief period of time as the lock moves from open to closed dirt can get there.
I then put the remaining small piece of blade into a piece of wood and hammered on it with a 600 metal bar (mild steel), driving it into the wood, much harder than would be necessary to split it (seasoned pine, six months). A dozen hits total, the lock held fine, the spine of the blade was chipping under the impact of the hits. For comparison, using a piece of wood as a baton on an Arc-Lock from Sog (X-Ray Vision) the lock exploded under far less impacts. I then held onto the blade while it was struck by a friend two dozen times. He started off light, and worked up to heavy swings that were indenting the steel liners. The lock held.
When I went to unlock Niemi's knife , the nob that opens the liners cracked off, so it suffered a fracture during the second session of hammering. Popping the knife apart with a butter knife. It still opened and closed fine and was there was still no play in the lock up.
In short, the lock is very secure and extremely strong, the level of impacts necessary to damage the mechanism would have long since shattered the blade, and even when it did give way, the lock did not disengage but remained in tack, just the release mechanism gave way. I would be very curious about the ability of the lock if 3V was used, if it was coated well you should be able to avoid crevice corrosion which would be the main problem. With the addition of 3V's high fracture strength the lock should then able to withstand even the above pounding, which is rather extreme. In any case, it is still the most secure and strong lock I have seen to date.
If the above lock performance surprises you (it did me), you need to realize that the size of the mating surfaces that engage are many times that of locks like liners and lockbacks. In order for this lock to release you need to exert a level of force which is of similar magnitude to break a blade vertically, this is *very* high. Try it even with a cheap butter knife to see how difficult.
-Cliff
http://www.bladeforums.com/forums/showthread.php?s=&threadid=235127
Initial lock testing :
1) White knuckle test. This can open lock backs and very frequently unlocks liner locks, I could open a Spyderco Military this way, after it had been adjusted at the factory for example. Niemi's lock actually needs the handle slabs to open for the lock to release so all that this does it reinforces the lock (this is of significant importance on several of the lock tests) .
2) Spine whack. Using both a light and whippy motion and a hard impact swing, the tip of the blade was struck against a piece of wood in order for the effects of sudden fast shocks and heavy impact loads to either induce impaction of the mating surfaces or have something just get jarred apart. None of this had any effect, I worked up to swinging the knife hard enough to dig 1/4"+ holes in cedar.
3) I took a 4 foot piece of cedar baseboard and reduced it to shavings. I then repeated it with a piece of hardwood baseboard, which had a lot of splintering, and general wood breakage, and thus increased the torque on the lock. I went as heavy as possible, quickly, to maximise the strain on the lock, with no care to eliminate torques. I also cut deeply and twisted to break the wood out, as well as jerked back to pop the blade free. No effect on the lock.
4) I put the point in a piece of 4x4 and twisted the grip trying to get the slabs to open. This wasn't possible, they are far too rigid. I then resorted to having a friend push on the 4x4 while holding the knife as tight as I could and all I could do was twist the knife out of my hand. This combination of twisting and vertical loads can easily causes most liner locks to disengage and even break. I broke the liner on a Buck/Strider doing this with far less effort.
5) With the blade tip in the wood (just inserted in a crack) I bent the knife until the handle was at 30 degrees off of perpendicular (the wood was giving somewhat so the angle includes that deformation as well), the blade now had a slight visible bend. The handle slabs did not open at all. Unloading the knife, the blade returned to straight and the lock was not effected. This was about the maximum I could bend the knife using just my wrist strength. Because of the thickness of the handle liners, they are too rigid to bend significantly.
In short, the above places it above any lock that I have seen so far in regards to both raw strength as well as security. Before I did anything harder I then did some cutting tests as the blade profile is actually quite interesting and offers quite high cutting performance. The blade has a primary hollow grind, which I would call hollow relief as it isn't "T" shaped hollow which can wedge tightly at the top of the grind. The primary edge profile is 0.028" thick and 0.083" wide which is less than 20 degrees included. On top of this there is a more obtuse secondary edge bevel just barely visible .
Stock cutting tests :
The blade could push cut 3/8" hemp at ~14 lbs near the base of the blade and ~22 lbs near the tip. The increase in force was just due to the tip being slightly blunter. It only took 6.2 (0.2) slices to point a one inch hardwood dowel. For reference, the Cold Steel Twistmaster took ~12 slices on the dowel, and ~40 lbs on the cord. The cutting performance is well above average.
Sharpening :
Before the stock tests, but after the above wood cutting, the blade would not shave any more so I stropped it on CrO, ten passes per side. The shaving edge returned and there was little evidence of a floppy burr. The knife was then used in the kitchen on ripe tomatoes and peppers which it handled fine. Clean cuts with no mashing. Works very well for that kind of use, more shortly. This stropping was repeated several times during the work with the blade, it restored the shaving finish each time.
General blade shape :
The blade looked odd at first, upswept, but it actually isn't. The point profile is traditional tanto, with the point inline with the spine. There is just a curve in the spine which makes the point appear to rise. This curvature makes the blade fit smoothly in the grip. The shape gives a lot of curvature near the tip which enhances slicing ability as well as rocking cuts. It works very well on vegetation in the kitchen for this reason, as well as the lack of a guard allows cuts full to the cutting board. In addition because the blade is sharpened fully back, no choil, it works well as a paring knife. It was also used to trim the fat from some chicken legs as well as do rocking cuts straight through the bone, no significant blunting was induced, let alone edge damage.
Handle :
The handle fills the hand well, and is decently secure, no slippage was noted. The inside of the inside S30V liners is a little square though and did cause some irritation with extended use. A guard would also be appreciated by some to enhance security on thrusts .
Flickability :
The lever that opens the lock (it engages when the knife is closed as well as open), takes 6-8 lbs to rotate. This isn't a huge amount of force, but it a lot more than a smooth liner lock. This isn't a lock that you are likely to flick open and close for entertainment. I did a short cycle of 250 opens and closes to see if any slack would develop and I had to stop every 50 times. That being said, I carried the knife for awhile and used it to cut anything regardless of how trivial, it quickly became second nature to open. I just popped it with my thumb while holding the knife steady in a sideways sort of pinch.
Heavy lock work :
I chopped a couple of sections of the hardwood baseboard in two. Using the Camp Tramp (Swart Rat knives), sitting down, just swinging from the elbow it chopped easily in 12-14 hits. Standing up, doing fully power swings, it would take 3-7, and the board would be falling apart under the impacts. The folder took 38-42 hits. It took as many because I was holding back on the grip and the hits were landing really sloppy. The penetration was very high for the impact energy. No effect on the lock.
The blade was loaded vertically with 869 in.lbs of torque (just a particular weight I had a hand). To put this in perspective, if you could lift a 8 lbs sledge hammer by the very end of the handle with one hand, you would be of above average strength - that is less than 300 in.lbs of torque. I attempted to apply more of a load but could not keep the blade in position. In any case, the amount of steel that you need to break to cause the lock to release is many times that of normal folders. The break strength would be insanely high .
The blade was loaded sideways to see if I could pop the handle apart enough to get the lock to release, here is where I made a mistake. I thought I was loading the blade with 250 in.lbs, as I approached the maximum the blade snapped cleanly in half. The blade didn't bend significantly before it broke, and it was perfectly straight after the snap. When I checked the lever arm again the maximum torque was 350 in.lbs. I would estimate it was 275 - 325 in.lbs when it broke.
[this cut short the cutting part of the review]
The lock was then examined to see how it would handle dirt in the mechanism. I took ash from the wood stove (which also is used as a dust pail in the basement) and pushed in into the lock from all directions once it was closed. The blade still engaged fully when the lever was thrown. I then jammed it full of ash and dirt again when it was open and then flipped the bar and closed it. No problem. I then repeated it a few times. Unlike many other locks this one has the mating surfaces fully engaged when both open and closed so they can't get contaminated. The only way for this to happen would be to open it in a really dirty situation so for the brief period of time as the lock moves from open to closed dirt can get there.
I then put the remaining small piece of blade into a piece of wood and hammered on it with a 600 metal bar (mild steel), driving it into the wood, much harder than would be necessary to split it (seasoned pine, six months). A dozen hits total, the lock held fine, the spine of the blade was chipping under the impact of the hits. For comparison, using a piece of wood as a baton on an Arc-Lock from Sog (X-Ray Vision) the lock exploded under far less impacts. I then held onto the blade while it was struck by a friend two dozen times. He started off light, and worked up to heavy swings that were indenting the steel liners. The lock held.
When I went to unlock Niemi's knife , the nob that opens the liners cracked off, so it suffered a fracture during the second session of hammering. Popping the knife apart with a butter knife. It still opened and closed fine and was there was still no play in the lock up.
In short, the lock is very secure and extremely strong, the level of impacts necessary to damage the mechanism would have long since shattered the blade, and even when it did give way, the lock did not disengage but remained in tack, just the release mechanism gave way. I would be very curious about the ability of the lock if 3V was used, if it was coated well you should be able to avoid crevice corrosion which would be the main problem. With the addition of 3V's high fracture strength the lock should then able to withstand even the above pounding, which is rather extreme. In any case, it is still the most secure and strong lock I have seen to date.
If the above lock performance surprises you (it did me), you need to realize that the size of the mating surfaces that engage are many times that of locks like liners and lockbacks. In order for this lock to release you need to exert a level of force which is of similar magnitude to break a blade vertically, this is *very* high. Try it even with a cheap butter knife to see how difficult.
-Cliff
). Seriously, I wonder if people are getting knives with a wire edge, and perceiving damage to that edge as "chipping", since my experience with the steel has been alot different.