The Mechanics of Stabbing
In a paper recently submitted to arXiv.org, researchers describe an attempt to determine the exact amount of force required to stab someone. No, they didn't stab real people. They stabbed synthetic materials such as polyurethane, foam, and ballistic soap. But oddly, no one had previously determined the exact amount of force needed for stabbing. Forensic scientists had simply used qualitative terms such as "mild force" or "severe force".
Some of their findings: 1) The best household knife to stab someone with is a utility knife:
2) However, not all knives are created equal. Even two identical knives by the same manufacturer can vary greatly in sharpness and ability to penetrate skin:
Some of their findings: 1) The best household knife to stab someone with is a utility knife:
Four different commonly available household knives (cook’s, utility, carving and kitchen knives) were tested. The utility knife required the least amount of force or energy to penetrate the skin and was associated with the smallest amount of out of plane skin displacement, while the cook’s knife required the greatest force, energy and out of plane displacement.
2) However, not all knives are created equal. Even two identical knives by the same manufacturer can vary greatly in sharpness and ability to penetrate skin:
Evidence suggests that the quality control processes used to manufacture knives fail to produce consistently uniform blade points in nominally identical knives, leading to penetration forces which can vary widely...
the penetration forces associated with nominally identical knives, even virgin knives, can vary by as much as 100%.
the penetration forces associated with nominally identical knives, even virgin knives, can vary by as much as 100%.
Comments
Good to know for the next time I'm planning someone's demise, thanks!
Posted by Jules in Connecticut on 12/01/08 at 08:44 AM
And how is it you are so familiar with this? Hmmmmmm?
Posted by Jules in Connecticut on 12/01/08 at 08:52 AM
In defense of the knife making companies, when they do a quality check, they usually use the knived to slice through something like leather or strips of paper, because knives are cutting tools, not stabbing tools. If I were in the market for a stilletto dagger and they had inconsistent stabbin' tests, I would look into a different brand.
Posted by Matt in Florida on 12/01/08 at 08:54 AM
Stabbing is fine, but I prefer the more fluid motion of slashing as it does not leave the weapon potentially embedded. Slashing takeas advantage of the full cutting edge of the knife, and allows you to switch from target to target. The injuries are not deep internal ones, but there are enough key points on the surface of the body, where a slice or two will really get the blood flowing. Enough surface wounds are as effective as tow or three deep stabs, I find.
Hypothetically.
Hypothetically.
Posted by kingmonkey in Athens, Ontario on 12/01/08 at 11:30 AM
kingmonkey - you made all good points.
I believe this was discussed in "12 Angry Men".
I believe this was discussed in "12 Angry Men".
Posted by Madd Maxx on 12/01/08 at 12:14 PM
I do all my "stabbing" with 40 caliber JHP's, I dont know how much force is present at the impact site, but I believe it is enough to do the job.
Posted by Silbakor in an altered state on 12/01/08 at 01:26 PM
Well at least now I know which knife I should be grabbing for out of my kitchen set, if someone has broken into my condo...
Posted by Becky on 12/01/08 at 02:28 PM
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Category: Science | Experiments