Blade Straightening

[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

[Federico]

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]

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]

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]

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]

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]

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.

[Ferguson]

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

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

Steve