Heat treatment - 5160 and water hardening

M

Moonw

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Nov 19, 2014
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I was looking at a video showing how the Filipinos differentially harden thier Bolos. Same spring steel, and same quenching agent - water.

They were dipping the blade edges in water, basically. So then I remembered that I was wondering what difference this would make as oposed to pouring water like the kamis do? 5160 being a deep-hardening steel, as far as I remember. The full edge is hardened, this is a difference I've observed (alhough with kukris I've sometimes seen the same, interestingly, as a side-note).

Here is the video, 10:43 shows the hardening process:

[video]https://m.youtube.com/watch?v=s_cGr_BD3kk[/video]

Fascinating!

P.S. Also, check the cool anvil :), see anything interesting?
 
Khul! That was very informative. Some interesting techniques for shaping. Its interesting to watch a pair of guys on the hammer and how they coordinate their strikes and harmonize. I could watch them all day. Like music to mine ears. Thx Moon:thumbup:
 
I found it interesting how it looked like at times one would deliberately not strike on the knife but would strike the anvil to maintain the rhythm. That could have been a trick of the camera though, as I noticed that a lot of times it looked like the hammer stopped a foot short of the anvil but still made the noise.
 
Scara, it seemed to me as well a few times but looking up closer it seemed to me that one was hammering the very end (edge?) of the blade. I didn't rewind, though, to when I 1st got the impression, so I might be off.

All others: YW, I thought this was very cool indeed. In case anyone didn't notice, the anvil was an old cannon :D.
 
A Cannon!
Some strikes seemed to stop in the air but thats probably just missed by the camera due to the frame rate. But there where some strikes where he clearly hit the canon on the far left. It seemed whenever he might have needed a break or readjust his grip on the hammer he just taps the anvil to stay in the rhythm so that the next hits on the blade will be synchronized with the second blade smith.
Once before he started he hit the anvil a couple of times until it was in sync and then proceeded to hit the blade.
Very cool to see. Seriously like two musicians.
:-)
 
Scara said:
I found it interesting how it looked like at times one would deliberately not strike on the knife but would strike the anvil to maintain the rhythm. That could have been a trick of the camera though, as I noticed that a lot of times it looked like the hammer stopped a foot short of the anvil but still made the noise.
Click to expand...

When i was younger I worked full time as an ornamental blacksmith (the smithing was ornamental, not me)-the off striking is a technique, sometimes to keep a rythm but see where the thing needs to be hit next.
I can see the poured water technique working with thick 5160, but quenching
it is usually not pretty at all-I'm continually amazed when it survives in the cross sections the Pinoy blades have.
I wonder if a lot of bolos are 1060 rather than 5160-I've talked to a rep from American Eagle springs and all their leaves (except the tapered ones) are 5160, but outside the US there's a lot of variation.
I've had 5160 chefs knives crack in canola oil, now and again.
 
If you watch the mark on the steel instead of the hammer it will come a bit more obvious what they are doing. If the second guy is in swing when the one holding the Khuk lifts it to inspect it or turn it or any other reason the guy in mid swing slows his swing down and strikes the anvil to let the hammer bounce back up. It also takes less energy to let the hammer bounce off the anvil face and prepare for the next strike than to actually stop the hammer and get back into rhythm.
Cannon anvil:eek: How khul is that?
 
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