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.50 cal vs. Katana

Posted: Sat Oct 21, 2006 9:28 am
by Chief Petty Officer Klerk

Posted: Sat Oct 21, 2006 2:24 pm
by wraith11
That's just insane...
...Can't belive it was actually slicing them for a time there.

Posted: Sat Oct 21, 2006 2:37 pm
by KiLlEr
That is true for almost any sword (except cavelry sword which are extreamly flexible, and stabing swords that have no real blade edge). hacking/slashing swords are made by folding over metal and pounding it for strength and weight (as you can see from the Katana as the actual layers have seperated) and have razor sharp edges to facilitate penetration of leather armor. Then the blade is heated, rapidly cooled, reheated and stuck in shit (which is high in carbon) to carbonize the edge. The bullet is at a loss, since its is made to fragment or deform upon impact to maximize damage with only enough hard metal to penetrate plate metal (the 50 cal looked like it was using jacketed rounds that are copper or brass over lead, both of which are softer than carbonized steel).

So its no surprize that the bullets split, but you can see that after each impact part of the blade was used up, melted by the impact. And if you notice the amount of damage to the blade increased on each hit. The first 2 hits stripped the carbonized surface, the next hit melted the edge, the successive hits then tore off chunks of steel. It is a very predictable pattern.

Posted: Sat Oct 21, 2006 3:52 pm
by Katyusha
Either way, it's a waste of stuff best used elsewhere... like slaying annoying co-workers.

Posted: Sun Oct 22, 2006 8:11 am
by Taurec
Japanese smiths certainly NOT stuck the blades in shit to carbonize the edge. As base material they used steel that already had a high carbon percentage.

Hardening 101

Most steel is capable of forming into any one of several different crystalline structures, each has different levels of hardness, toughness and flexibility. Changing from any structure to another needs a lot of heat.

Traditional Japanese blades are selectively hardened. 10 centuries ago, Japanese smiths developed a metallurgical process (used no place else on this planet) which gave Japanese swords their unique combination of strength and cutting ability.

Getting back to the crystalline structure, their blades are composed of a very hard crystalline structure called martensite, while the spines are composed of softer but tougher structures called pearlite and ferrite.

Martensite is formed in carbon steels by heating the steel to what is known as its "critical point" – a temperature at which the steel begins to assume a more plastic structure called austenite. If allowed to cool slowly, the austenite will precipitate into pearlite again.
However, when high carbon steel is quenched in a cooling medium such as water, the steel forms a martensitic (hard) structure.

It is this peculiarity which is exploited by the Japanese smiths to form the differentially hardened blade.
By using an ancient technique of "clay coating" which was developed centuries ago in Japan, they would coat the spine of the blade with clay leaving the edge uncoated.
When they then heat the blade to the critical temperature and quench the blade in water. The clay on the spine acts as a heat sink so that the spine cools more slowly than does the edge – too slowly to cause it to harden.
In metallurgical terms: the edge steel converts from austenite to martensite while the spine converts to pearlite and ferrite.
Meaning: hard edge, soft back. Then they temper the blade to reduce stresses in the steel.

Posted: Sun Oct 22, 2006 2:44 pm
by KiLlEr
I wasn't speaking specifically of the Katana there Tau. :)

My point was that what happens in the video does not surprise me, and its little to do with the fact that it was a Japanese sword. Any non-cavalry sword designed to hack and slash would have the same results.

Posted: Wed Oct 25, 2006 8:49 pm
by HELLFIRE
...short version: you with Yagu Jubei skills on one side and the other guy
with a .50cal MG on the other, you're gonna have yer ass handed to you...

Nice find CPOK!





Regards

Posted: Thu Oct 26, 2006 1:48 am
by KiLlEr
JUBEICHAN!!!!!!!!!

Image

pucha pucha no purin purin no bon bons !!!