Blade Straightening

Jeff D · 29th January 2005, 09:10 PM

Hi All,

I have a M1927 Soviet shashka with a slightly bent blade. Does anyone have any tricks to straighten it.

Thanks in advance for any replies.
Jeff

Federico · 29th January 2005, 09:36 PM

Quote:

Originally Posted by Jeff D

Hi All,

I have a M1927 Soviet shashka with a slightly bent blade. Does anyone have any tricks to straighten it.

Thanks in advance for any replies.
Jeff

Wood blocks and a vice could work. So could gentle bending on the knee. Ive done both to straighten somewhat bent blades. But then again, I have not been going for perfect straight, but rather straighter than say a 90 degree bend. At some point, if one cant straighten fully, there is the danger of creating an S bend. Ive heard of some people pounding such bends out on an anvil. But then I am paranoid with antiques. Rather have a slight curve, than a broken sword.

Jeff D · 30th January 2005, 02:17 AM

Thanks Federico,

It is exactly the S bend I was wondering if anyone knew any tricks to avoid. I was also wondering if there is any thing needed to avoid snapping the blade, or any other trade secrets to get it perfectly straight.

Thanks again.
Jeff

Federico · 30th January 2005, 05:57 AM

Long wood blocks in the vice may be the best way to avoid the S bend. Slowly tighten the vice, and the wood blocks should straighten it fine. However, without playing with heat (which of course could ruin the temper), straightening it out you really just gotta hope it was tempered right, and work slow (eg. the vice should be slow enough).

Justin · 30th January 2005, 04:47 PM

I have re-straightened many blades and have never snapped one .The best thing I have found to do is use a dead-blow hammer lay the blade against ahard and flat surface and hit it with as little force as possible.Generally this doesnt work too well on springy blades and I have often resorted to leaving them alone just to be on the safe side.
Fredricos vice method would work as well but I would be very gentle.....

Jens Nordlunde · 30th January 2005, 05:06 PM

Quote:

Originally Posted by Justin

I have re-straightened many blades and have never snapped one .The best thing I have found to do is use a dead-blow hammer lay the blade against ahard and flat surface and hit it with as little force as possible.Generally this doesnt work too well on springy blades and I have often resorted to leaving them alone just to be on the safe side.
Fredricos vice method would work as well but I would be very gentle.....

When you use a hammer, do you hammer directly on the blade, or do you have something in between?

Jens

tom hyle · 30th January 2005, 05:12 PM

This is probably a spring-tempered blade. You may be in luck if the bend is at a soft forte, but otherwise may be very hard to straighted. If you use a hammer, use a hammer and anvil of softer material than the blade; copper, lead, and rubber all come recommended. You're not going to get any results with a spring-tempered blade unless you go considerably past the results you want and let it come "back"; this is tricky at best, in terms of both angle and placement (avoiding the "s"). Locallizing the bend can involve clamping one straight part in a vice with padded, preferably round-topped, jaws, and bending it by hand or with another clamp. This is the method most likely to stress or crack your blade (though Justin is quite correct that decent old swords very rarely break). Alternately, you can use 3 blocks in a vice, so one pushes the bend "down" between the other two. This method can give great pecision on softer-than-spring blades. Many old spring-tempered blades are at a soft-spring temper; springy, but a little softer than a true spring temper, and can be bent. True spring tempered blades commonly get bent during hardening, when the steel crystals change size. Such bends, called "casts", are usually gradual. Convincing speculation is that locallized bends arise when blades are thrust through bone, and get tightly "kinked" over it in the death-throes or withdrawal (this is an especially convinving scenario for cavalry swords), or possibly that the strain of a thrust-flex, perhaps on encountering armour or bone, can be too instantaneous for the springiness to fully absorb. Such acquired bends, occasionally intentionally formed by or for swordsmen, as well, are called "setts".
There's a booklet, usually available on the internet, that claims to inform as to straightening swords and gun barrels. I haven't read it; just thought I'd mention it.

tom hyle · 30th January 2005, 05:19 PM

I think Justin is talking about a dead-blow mallet made of flexible hard platic with a floating/sliding sand(?)-load that shifts from the handle into the head as you swing. It's surface shouldn't mar steel, though I've really only used them on wood. Mind the anvil though.

Ferguson · 30th January 2005, 05:25 PM

I've never done it, but the method shown here looks promising.

http://www.ksky.ne.jp./~sumie99/togi,process.html

Steve

Jeff D · 30th January 2005, 05:28 PM

Thanks Guys,

It is a spring tempered blade, so that simply straightening it out doesn't work, it "springs" back as soon as it is out of the vice. I think the three block technique might work. I might suck up the courage to do it this afternoon and will post the results.

Thanks again.
Jeff

Jeff D · 30th January 2005, 05:32 PM

Quote:

Originally Posted by Ferguson

I've never done it, but the method shown here looks promising.

http://www.ksky.ne.jp./~sumie99/togi,process.html

Steve

Thanks for the link Steve, that does look simple.

Jeff

tom hyle · 30th January 2005, 05:51 PM

Nice clamp; I don't know that it'll help much with the spring temper issue. Japanese swords, are, of course, soft, with hardened edges, and sometimes approximately spring-tempered skin-steel over a soft core; much easier to bend. The tool that used to sett the teeth of saws (called a saw-sett) is a tiny vice that works by the 3-blocks method. So on a small scale this is a routine procedure. Remember though, that this point has already been stressed; I've encountered people who prefer to rebend to a slight "s" for this reason; to not double-stress the same exact spot, but one 1/2 inch over along the blade.

Tim Simmons · 30th January 2005, 09:58 PM

Hello Jeff ,I would only straighten a blade if it was bad on the eye.I have a sabre that has obviously been used in battle,if one was to slash a head at say 20-30 mph, most swords are going to bend ,most of all around the last 12 inches or so.To make it straight would be to take all the life out of the sword.I would only take the very worst bends out.Tim.

Jeff D · 30th January 2005, 10:40 PM

Thanks Tim,

The bend itself isn't that bad, but it does make it tight in the scabbard. It should still have some "life" in it as there are plenty of other marks. Including three notches on the grip which I personally hope only represent wear and tear (I am one of those squeamish collectors).

Jeff

erlikhan · 31st January 2005, 02:20 AM

i am not so sure but ,i think i had heard from somebody that it could be straightened by some manner of heating and cooling back after getting reshaped. It is possible even to repair broken swords that way, and possible to apply makeup to it to erase the tracks of the repair and obtain a homogenous looking. I will ask that guy tomorrow or the day after once more for more detail.

29th January 2005, 09:10 PM	#1
Jeff D Member Join Date: Dec 2004 Location: B.C. Canada Posts: 473	Blade Straightening Hi All, I have a M1927 Soviet shashka with a slightly bent blade. Does anyone have any tricks to straighten it. Thanks in advance for any replies. Jeff

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30th January 2005, 02:17 AM	#3
Jeff D Member Join Date: Dec 2004 Location: B.C. Canada Posts: 473	Thanks Federico, It is exactly the S bend I was wondering if anyone knew any tricks to avoid. I was also wondering if there is any thing needed to avoid snapping the blade, or any other trade secrets to get it perfectly straight. Thanks again. Jeff

30th January 2005, 05:57 AM	#4
Federico Member Join Date: Dec 2004 Location: Minneapolis, MN, USA Posts: 312	Long wood blocks in the vice may be the best way to avoid the S bend. Slowly tighten the vice, and the wood blocks should straighten it fine. However, without playing with heat (which of course could ruin the temper), straightening it out you really just gotta hope it was tempered right, and work slow (eg. the vice should be slow enough).

30th January 2005, 04:47 PM	#5
Justin Member Join Date: Dec 2004 Posts: 175	I have re-straightened many blades and have never snapped one .The best thing I have found to do is use a dead-blow hammer lay the blade against ahard and flat surface and hit it with as little force as possible.Generally this doesnt work too well on springy blades and I have often resorted to leaving them alone just to be on the safe side. Fredricos vice method would work as well but I would be very gentle.....

30th January 2005, 05:12 PM	#7
tom hyle Member Join Date: Dec 2004 Location: Houston, TX, USA Posts: 1,254	This is probably a spring-tempered blade. You may be in luck if the bend is at a soft forte, but otherwise may be very hard to straighted. If you use a hammer, use a hammer and anvil of softer material than the blade; copper, lead, and rubber all come recommended. You're not going to get any results with a spring-tempered blade unless you go considerably past the results you want and let it come "back"; this is tricky at best, in terms of both angle and placement (avoiding the "s"). Locallizing the bend can involve clamping one straight part in a vice with padded, preferably round-topped, jaws, and bending it by hand or with another clamp. This is the method most likely to stress or crack your blade (though Justin is quite correct that decent old swords very rarely break). Alternately, you can use 3 blocks in a vice, so one pushes the bend "down" between the other two. This method can give great pecision on softer-than-spring blades. Many old spring-tempered blades are at a soft-spring temper; springy, but a little softer than a true spring temper, and can be bent. True spring tempered blades commonly get bent during hardening, when the steel crystals change size. Such bends, called "casts", are usually gradual. Convincing speculation is that locallized bends arise when blades are thrust through bone, and get tightly "kinked" over it in the death-throes or withdrawal (this is an especially convinving scenario for cavalry swords), or possibly that the strain of a thrust-flex, perhaps on encountering armour or bone, can be too instantaneous for the springiness to fully absorb. Such acquired bends, occasionally intentionally formed by or for swordsmen, as well, are called "setts". There's a booklet, usually available on the internet, that claims to inform as to straightening swords and gun barrels. I haven't read it; just thought I'd mention it.

30th January 2005, 05:19 PM	#8
tom hyle Member Join Date: Dec 2004 Location: Houston, TX, USA Posts: 1,254	I think Justin is talking about a dead-blow mallet made of flexible hard platic with a floating/sliding sand(?)-load that shifts from the handle into the head as you swing. It's surface shouldn't mar steel, though I've really only used them on wood. Mind the anvil though.

30th January 2005, 05:25 PM	#9
Ferguson Member Join Date: Dec 2004 Location: Kernersville, NC, USA Posts: 793	I've never done it, but the method shown here looks promising. http://www.ksky.ne.jp./~sumie99/togi,process.html Steve

30th January 2005, 05:28 PM	#10
Jeff D Member Join Date: Dec 2004 Location: B.C. Canada Posts: 473	Thanks Guys, It is a spring tempered blade, so that simply straightening it out doesn't work, it "springs" back as soon as it is out of the vice. I think the three block technique might work. I might suck up the courage to do it this afternoon and will post the results. Thanks again. Jeff

30th January 2005, 05:51 PM	#12
tom hyle Member Join Date: Dec 2004 Location: Houston, TX, USA Posts: 1,254	Nice clamp; I don't know that it'll help much with the spring temper issue. Japanese swords, are, of course, soft, with hardened edges, and sometimes approximately spring-tempered skin-steel over a soft core; much easier to bend. The tool that used to sett the teeth of saws (called a saw-sett) is a tiny vice that works by the 3-blocks method. So on a small scale this is a routine procedure. Remember though, that this point has already been stressed; I've encountered people who prefer to rebend to a slight "s" for this reason; to not double-stress the same exact spot, but one 1/2 inch over along the blade.

30th January 2005, 09:58 PM	#13
Tim Simmons Member Join Date: Dec 2004 Location: What is still UK Posts: 5,807	Hello Jeff ,I would only straighten a blade if it was bad on the eye.I have a sabre that has obviously been used in battle,if one was to slash a head at say 20-30 mph, most swords are going to bend ,most of all around the last 12 inches or so.To make it straight would be to take all the life out of the sword.I would only take the very worst bends out.Tim.

30th January 2005, 10:40 PM	#14
Jeff D Member Join Date: Dec 2004 Location: B.C. Canada Posts: 473	Thanks Tim, The bend itself isn't that bad, but it does make it tight in the scabbard. It should still have some "life" in it as there are plenty of other marks. Including three notches on the grip which I personally hope only represent wear and tear (I am one of those squeamish collectors). Jeff

31st January 2005, 02:20 AM	#15
erlikhan Member Join Date: Dec 2004 Location: Istanbul Posts: 452	i am not so sure but ,i think i had heard from somebody that it could be straightened by some manner of heating and cooling back after getting reshaped. It is possible even to repair broken swords that way, and possible to apply makeup to it to erase the tracks of the repair and obtain a homogenous looking. I will ask that guy tomorrow or the day after once more for more detail.