Technical question

PUFF · 9th May 2006, 03:38 AM

Many blades often have a degree of twisting after heat treatment. But if the twist 's acceptable (by the smith and the owner), they usually left as is. Japanese smiths have less tolerance for blade twisting and they correct this problem with a couple of special sticks.

Ian · 9th May 2006, 01:58 PM

Quote:

Originally Posted by PUFF

Japanese smiths have less tolerance for blade twisting and they correct this problem with a couple of special sticks.

PUFF:

Can you elaborate on this method? What were the special sticks and how were they used?

Ian.

Mark · 9th May 2006, 03:05 PM

Twisting is very common in dha & daab. Its pretty hard to say whether it is "original" or a later deformation from use or mistreatment.

athena · 9th May 2006, 03:18 PM

In long blade, twisting is common. And the twist may change along with time.

Jeff Pringle · 9th May 2006, 03:31 PM

It is very easy to get a twist during the forging of a blade, all it requires is not holding the blade, or the hammer, at a uniform angle as you forge over the whole length of the sword. Double-edged swords give you double the chance to make this mistake. Twists also show up in the heat treating, but this is less common than forging them in.
Swords heat treated in the Japanese manner (hard edge, soft back) are remarkably easy to straighten compared to fully quenched (hard all the way through) blades – the trade off is they are also remarkably easy to bend.
Bending forks (which look like this:╒ ) are used to take out twists by placing the blade in a vise at the start of the twist, and applying torque with the blade between the prongs of the fork.
Twists are controlled by careful forging, careful heat treatment, and careful remedial untwisting during the finishing process, but hopefully if you do a good job on the first two, you don’t need the third.

Battara · 9th May 2006, 08:10 PM

I think it is a good question. I have noticed this also in some dha and Moro kris (not in barong or kampilan however) and some Northern PI matulis. I thought it was something in the forging and/or in the usage. Not sure of the answer myself.

9th May 2006, 03:38 AM	#1
PUFF Member Join Date: Feb 2006 Location: 30 miles north of Bangkok, 20 miles south of Ayuthaya, Thailand Posts: 224	Many blades often have a degree of twisting after heat treatment. But if the twist 's acceptable (by the smith and the owner), they usually left as is. Japanese smiths have less tolerance for blade twisting and they correct this problem with a couple of special sticks.

9th May 2006, 03:05 PM	#3
Mark Member Join Date: Dec 2004 Posts: 987	Twisting is very common in dha & daab. Its pretty hard to say whether it is "original" or a later deformation from use or mistreatment.

9th May 2006, 03:18 PM	#4
athena Member Join Date: Apr 2006 Posts: 42	In long blade, twisting is common. And the twist may change along with time.

9th May 2006, 03:31 PM	#5
Jeff Pringle Member Join Date: Nov 2005 Posts: 189	It is very easy to get a twist during the forging of a blade, all it requires is not holding the blade, or the hammer, at a uniform angle as you forge over the whole length of the sword. Double-edged swords give you double the chance to make this mistake. Twists also show up in the heat treating, but this is less common than forging them in. Swords heat treated in the Japanese manner (hard edge, soft back) are remarkably easy to straighten compared to fully quenched (hard all the way through) blades – the trade off is they are also remarkably easy to bend. Bending forks (which look like this:╒ ) are used to take out twists by placing the blade in a vise at the start of the twist, and applying torque with the blade between the prongs of the fork. Twists are controlled by careful forging, careful heat treatment, and careful remedial untwisting during the finishing process, but hopefully if you do a good job on the first two, you don’t need the third.

9th May 2006, 08:10 PM	#6
Battara EAAF Staff Join Date: Dec 2004 Location: Louisville, KY Posts: 7,280	I think it is a good question. I have noticed this also in some dha and Moro kris (not in barong or kampilan however) and some Northern PI matulis. I thought it was something in the forging and/or in the usage. Not sure of the answer myself.