Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Awhile ago Donna Barnas started a thread on the evaluation of fighting blades and Steve Harvey commented in detail concerning what such a blade should be able to do and how you could look at it :
http://www.bladeforums.com/ubb/Forum3/HTML/001879.html
There were a couple of things that I had never tried and was curious about how stressful they were. I finally managed to get a length of chain (3 feet) and with the help of a friend spent some time beating on a blade.
I first had him try to knock the blade out of my hand, this was in no way possible. I was using a big blade (18") so I had to fight considerable torque, but all it did was knock the blade around a bit, I never felt any slippage. Based on this, I don't see it as remotely possible that a smaller knife like a folder could ever be knocked out of your grip unless you are holding it very loose.
Next I just had him swing the chain starting with low force and working up to a full powered swing and I interscpeted it with the blade. I tried to just stop the chain, and also to deflect it as well as actually reverse the motion. In none of this I was successful, I would assume someone who knew what they were doing might be. End result I concluded that I had no chance to control the chains motion in any significant manner. However I could easily control which part of the blade was going to see the impact so I could protect the edge of the blade.
How was the edge effected? It suffered significant dents. It never chipped, but some of the dents were so severe that the metal was pushed past the plastic deformation limit and then broke away. The most extreme dent was about 0.5" wide and 0.2" deep. At this depth the edge thickness was 0.042. What does this look like -
Some specifics on the steel, the blade is a Barteaux Machete and it is spring steel and left fairly soft (vague I know, no RC available). It is very durable and very resistant to chipping. The damage described above is far less that what I saw on the Ontario machetes on wood. Note as well that I have cut the bevel down to a very thin 6-7 degrees.
Conclusion? If you had asked me before hand to describe the outcome I would have vastly overestimated the damage. I was surprised that the blade held up as well as it did. I didn't expect it to fracture, but given the very acute edge I assumed the dents would have been more severe, aside from the one bad dent, I had seen similar dents just on hard wood chopping. The fact is that unless you tried to actually chop into an incoming object I can't see the blade being damaged much at all, as the picture shows there was only one really bad dent which is when I tried that a few times.
So blocking is out as a cause of this kind of damage as far as I can tell, however if someone was actually skilled at this it would be easily possible for them to exert more control over the incoming object and thus place more stress on the blade. As well there is still the possibilty of you making a cut and someone blocking you with a hard object like a chain or pipe. In this case you could easily create a stituation where the stress would be similar to what caused the large dent.
So is Steves 50% cutting ability after blocking possible? When I first read his post I assumed that it was not in the slightest. However since most "tactical" blades are bevelled *much* more obtuse than the machete, as well as being made out of much stronger steels I now think that yes it is possible. The critical factor would be are they tough enough to handle high energy impacts off of hard contacts and not fracture - I don't know. I have some more blades to experiment with though.
-Cliff
[This message has been edited by Cliff Stamp (edited 08-11-2000).]
http://www.bladeforums.com/ubb/Forum3/HTML/001879.html
There were a couple of things that I had never tried and was curious about how stressful they were. I finally managed to get a length of chain (3 feet) and with the help of a friend spent some time beating on a blade.
I first had him try to knock the blade out of my hand, this was in no way possible. I was using a big blade (18") so I had to fight considerable torque, but all it did was knock the blade around a bit, I never felt any slippage. Based on this, I don't see it as remotely possible that a smaller knife like a folder could ever be knocked out of your grip unless you are holding it very loose.
Next I just had him swing the chain starting with low force and working up to a full powered swing and I interscpeted it with the blade. I tried to just stop the chain, and also to deflect it as well as actually reverse the motion. In none of this I was successful, I would assume someone who knew what they were doing might be. End result I concluded that I had no chance to control the chains motion in any significant manner. However I could easily control which part of the blade was going to see the impact so I could protect the edge of the blade.
How was the edge effected? It suffered significant dents. It never chipped, but some of the dents were so severe that the metal was pushed past the plastic deformation limit and then broke away. The most extreme dent was about 0.5" wide and 0.2" deep. At this depth the edge thickness was 0.042. What does this look like -

Some specifics on the steel, the blade is a Barteaux Machete and it is spring steel and left fairly soft (vague I know, no RC available). It is very durable and very resistant to chipping. The damage described above is far less that what I saw on the Ontario machetes on wood. Note as well that I have cut the bevel down to a very thin 6-7 degrees.
Conclusion? If you had asked me before hand to describe the outcome I would have vastly overestimated the damage. I was surprised that the blade held up as well as it did. I didn't expect it to fracture, but given the very acute edge I assumed the dents would have been more severe, aside from the one bad dent, I had seen similar dents just on hard wood chopping. The fact is that unless you tried to actually chop into an incoming object I can't see the blade being damaged much at all, as the picture shows there was only one really bad dent which is when I tried that a few times.
So blocking is out as a cause of this kind of damage as far as I can tell, however if someone was actually skilled at this it would be easily possible for them to exert more control over the incoming object and thus place more stress on the blade. As well there is still the possibilty of you making a cut and someone blocking you with a hard object like a chain or pipe. In this case you could easily create a stituation where the stress would be similar to what caused the large dent.
So is Steves 50% cutting ability after blocking possible? When I first read his post I assumed that it was not in the slightest. However since most "tactical" blades are bevelled *much* more obtuse than the machete, as well as being made out of much stronger steels I now think that yes it is possible. The critical factor would be are they tough enough to handle high energy impacts off of hard contacts and not fracture - I don't know. I have some more blades to experiment with though.
-Cliff
[This message has been edited by Cliff Stamp (edited 08-11-2000).]