Info Favorites Register Log in
myArmoury.com Discussion Forums

Forum index Memberlist Usergroups Spotlight Topics Search
Forum Index > Historical Arms Talk > So how do you test a sword Reply to topic
This is a standard topic Go to page 1, 2  Next 
Author Message
Russ Ellis
Industry Professional




Joined: 20 Aug 2003
Reading list: 42 books

Posts: 2,608

PostPosted: Tue 30 Nov, 2004 12:35 pm    Post subject: So how do you test a sword         Reply with quote

Okay so I'm wondering how do you insure a sword is a good one without testing it to destruction? The post that Matt made in the off topic forum and the pictures of the failure of my ex-Grosse Messer have me a bit upset. That sword sat in my safe for around two years or so. I had used it for some light cutting and figured that all was well with the world. Matt uses it for basically the first time and that day it fails. Now all the rest of the stuff in my safe is much higher end then the Cold Steel sword however, how do I REALLY know that I don't have another lemon in there somewhere?
TRITONWORKS Custom Scabbards
View user's profile Send private message
Joe Fults




Location: Midwest
Joined: 02 Sep 2003

Posts: 3,646

PostPosted: Tue 30 Nov, 2004 1:02 pm    Post subject:         Reply with quote

I would have said swing it at a pumpkin but...
"The goal shouldn’t be to avoid being evil; it should be to actively do good." - Danah Boyd
View user's profile Send private message
Chris Holzman





Joined: 24 Aug 2003

Posts: 124

PostPosted: Tue 30 Nov, 2004 1:22 pm    Post subject: Re: So how do you test a sword         Reply with quote

Russ Ellis wrote:
Okay so I'm wondering how do you insure a sword is a good one without testing it to destruction? The post that Matt made in the off topic forum and the pictures of the failure of my ex-Grosse Messer have me a bit upset. That sword sat in my safe for around two years or so. I had used it for some light cutting and figured that all was well with the world. Matt uses it for basically the first time and that day it fails. Now all the rest of the stuff in my safe is much higher end then the Cold Steel sword however, how do I REALLY know that I don't have another lemon in there somewhere?


From the pictures, it looks to me like that blade had a pre-existing failure, in the dark spot, which was further aggravated by the cut, causing it to snap. I've seen it hundreds of times over the last 10 years, with fencing blades. careful inspection for cracks is one way to try to predict problems. The other big question is if there is enlarged grain structure in the area around the break. that is a very common thing on fencing blades. its ODD for a failure down around the shoulder though, and is generally cause for a refund in the fencing world. we expect blades to break in the weak half, but now down that low.

There are also machines that the FIE uses to electronically detect micro-cracks in blades - I don't know anything about them or how they work, but they are used during weapons safety/check at World Cup and Olympics to the best of my knowledge. as I understand it, they're very expensive machines.

Chris Holzman
River City Fencing Club
Wichita, KS
View user's profile Send private message
Russ Ellis
Industry Professional




Joined: 20 Aug 2003
Reading list: 42 books

Posts: 2,608

PostPosted: Tue 30 Nov, 2004 1:25 pm    Post subject: Re: So how do you test a sword         Reply with quote

Chris Holzman wrote:
Russ Ellis wrote:
Okay so I'm wondering how do you insure a sword is a good one without testing it to destruction? The post that Matt made in the off topic forum and the pictures of the failure of my ex-Grosse Messer have me a bit upset. That sword sat in my safe for around two years or so. I had used it for some light cutting and figured that all was well with the world. Matt uses it for basically the first time and that day it fails. Now all the rest of the stuff in my safe is much higher end then the Cold Steel sword however, how do I REALLY know that I don't have another lemon in there somewhere?


From the pictures, it looks to me like that blade had a pre-existing failure, in the dark spot, which was further aggravated by the cut, causing it to snap. I've seen it hundreds of times over the last 10 years, with fencing blades. careful inspection for cracks is one way to try to predict problems. The other big question is if there is enlarged grain structure in the area around the break. that is a very common thing on fencing blades. its ODD for a failure down around the shoulder though, and is generally cause for a refund in the fencing world. we expect blades to break in the weak half, but now down that low.

There are also machines that the FIE uses to electronically detect micro-cracks in blades - I don't know anything about them or how they work, but they are used during weapons safety/check at World Cup and Olympics to the best of my knowledge. as I understand it, they're very expensive machines.


On this particular blade there were no visible cracks that I noticed and apparently some of the Albion folks were at this particular gathering and also noticed nothing wrong with it. An expensive machine also does not seem practical?

Other thoughts?

Thanks for the interesting info as well Chris!

TRITONWORKS Custom Scabbards


Last edited by Russ Ellis on Tue 30 Nov, 2004 1:33 pm; edited 1 time in total
View user's profile Send private message
Keith Larman
Industry Professional



Location: Sunny Southern California
Joined: 21 Aug 2003

Posts: 237

PostPosted: Tue 30 Nov, 2004 1:27 pm    Post subject:         Reply with quote

I get that question all the time. And the fact of the matter is that you never know. We managed to shatter a "popular beater" 5160 katana last year and were amazed that it happened. There were a couple very knowledgable smiths there at the time and the consensus was that the blade was somehow grossly overheated during heat treatment. But you wouldn't have known it from looking at it. But once it shattered, the huge grain was obvious. We had locked the blade down while someone took a huge edge to edge swing at it with an L6 blade by Howard Clark. The L6 took some edge damage (but not all the way through the hardened edge) but the 5160 blade actually shattered elsewhere down the blade. A slight nick on the soft back of the blade essentially propogated due to the force and vibration and the whole thing just snapped. Wild.

The obvious answer is that if you know the steel, know the maker, know who did the heat treating, well, there's where the faith has to come into play. And why folk can get pretty anal about insisting on safety measures when test cutting (or even just swinging in the air).

The traditional points in Japanese swords is to look for hairline cracks, irregularities in the steel, etc. A fairly common place to see those things is up in the monouchi (cutting area) and near the notches. Sometimes poor fitting of a habaki can start a crack there due to whacking it too hard to fit it. Those small cracks, especially if the blade has a thin edge, can themselves propogate and eventually become failure points.

And fwiw, I was speaking with a Japanese smith recently about heat treatment and what you "know" from the activities. He commented that one reason for the heat treatment with the hard edge and soft back combined with the polishing method was that if the treatment was done correctly, the hamon appeared and other "signs" became visible. A "sleepy" blade (the hamon is indistinct, wide, or diffuse) was likely no good. Same with blades where the hamon ran off the edge mid blade or ran too far back on the blade. Also, things like the existance of certain activity in the steel was a sign of a nailed heat treat. And the existance of other things (ara-nie -- course large surface grain which polishing makes visible) were bad things and signs of a brittle blade. Old blades with no hamon or very "soft" hamon were possibly damaged in a fire. Blades with certain signs of odd angled hamon near the notches at the habaki were signs of a blade that might have been re-quenched (possibly due to fire damage). And so forth. So the whole polishing deal wasn't all just about aesthetics, but was also intended to put a "window" into the steel to see exactly what was going on with it. Which makes it easier to determine if the blade is one that you could trust.

Just fwiw as an odd tangent...

Keith Larman
http://www.summerchild.com
View user's profile Send private message Send e-mail Visit poster's website
Russ Ellis
Industry Professional




Joined: 20 Aug 2003
Reading list: 42 books

Posts: 2,608

PostPosted: Tue 30 Nov, 2004 1:32 pm    Post subject:         Reply with quote

Hmmm thanks Keith, I appreciate the insight. Disappointing that there is no way to "know."
TRITONWORKS Custom Scabbards
View user's profile Send private message
Keith Larman
Industry Professional



Location: Sunny Southern California
Joined: 21 Aug 2003

Posts: 237

PostPosted: Tue 30 Nov, 2004 1:35 pm    Post subject:         Reply with quote

Howard Clark has talked about a machine that I believe uses electromagnetics to identify micro-fractures. Cracks alter the magnetic field causing filings to bunch up differently over cracks. Don't know much more about that, however. Nor how useful it would be with a mounted blade. One thing I like about the Japanese approach of fully disassemble-able (is that a word?) blades is that you can get down to the bare blade easily and really give it a close look. If the handle, guard, etc. are on permanently, well, that's a different problem.

One interesting note -- I've got an old blade that Bob Engnath was working on when he died. So the blade was quenched but never finished. One concern I had was that I didn't know if it "survived" heat treatment right. Why didn't Bob finish it? Maybe he didn't have time. Or maybe it made a snapping sound during quenching and he set it aside. I didn't know. But I bought it after looking it over in person because the blade had developed a bit of surface rust. And when cracked blades rust the rust tends to form in the cracks creating visible lines. Not a practical answer, of course, since it would entail letting your blades rust a bit, but fwiw just a bit more info...

And hey, Chris, how you been? Haven't heard from you in a while. Some of your finishing work has been really nice looking. I hope you stick to it...

Keith Larman
http://www.summerchild.com
View user's profile Send private message Send e-mail Visit poster's website
Chris Holzman





Joined: 24 Aug 2003

Posts: 124

PostPosted: Tue 30 Nov, 2004 1:40 pm    Post subject: Re: So how do you test a sword         Reply with quote

I agree with Keith - its simply hard to tell.

One thing you can do, is put a slight flex (BARELY a couple of degrees) on the blade in each direction, and run a piece of very thin shimstock along the blade corners, on the edge of the shim stock, and feel for it catching... that might help id cracks. I've done it with fencing blades with some success - but generally in areas where I already suspect a problem.

Otherwise, its often impurities and bad heat treat that cause a problem. typically fencing blades that break will show an area of enlarged grain on the area of the break. it takes a lot of work to snap one where there isn't some sort of flaw.

It's just hard to know.


Reference the machine Howard mentioned, I think these are one in the same. I believe the fencing weapons are checked fully mounted, with clamps/sensors at each end of the section tested. I'm not sure about that, but I know they can't be disassembling and reassembling peoples weapons, because they'll only have a matter of seconds to check each weapon, and taking apart/putting back together is going to take several minutes per weapon - and of course these are wired blades with screw on spring points and terminals at the end..
Chris

PS,

Hi Keith, I've been doing fairly well, haven't touched anything swordlike lately though, well, not since that habaki. I've been hunkered down with the law school thing - and fencing my butt off. Over the coming break, I'm going to be knocking out a couple of euro scabbard cores, and tryting to get with GaryB, to see about grinding out a tanto or two. I'll shoot you an email later, I've had a couple of questions rattling around, but have been too busy to ask them. Hope all is well with you.

Chris Holzman
River City Fencing Club
Wichita, KS


Last edited by Chris Holzman on Tue 30 Nov, 2004 1:48 pm; edited 1 time in total
View user's profile Send private message
Patrick Kelly




Location: Wichita, Kansas
Joined: 17 Aug 2003
Reading list: 42 books

Spotlight topics: 2
Posts: 5,739

PostPosted: Tue 30 Nov, 2004 1:44 pm    Post subject:         Reply with quote

Unfortunately there's no way you're going to know *for sure* without actually using the thing.

Usually I'll cut a few tatami mats with a new sword, maybe something like a pumpkin if it's in season. Usually that's about it unless it's a sword that's going to see a lot of cutting practice.

IMHO it's far more important to choose a manufacturer with a good grasp of the craft and a good reputation, than it is to worry about it after the purchase. Everyone puts out a bad one now and then but a good reputation for quality control goes a long way towards allaying this. In the case of Cold Steel their swords are being carried on the reputation of their knives. A reputation which Cold Steel swords don't live up to.

"In valor there is hope.".................. Tacitus
View user's profile Send private message AIM Address
Russ Ellis
Industry Professional




Joined: 20 Aug 2003
Reading list: 42 books

Posts: 2,608

PostPosted: Tue 30 Nov, 2004 1:54 pm    Post subject:         Reply with quote

Patrick Kelly wrote:
Unfortunately there's no way you're going to know *for sure* without actually using the thing.

Usually I'll cut a few tatami mats with a new sword, maybe something like a pumpkin if it's in season. Usually that's about it unless it's a sword that's going to see a lot of cutting practice.

IMHO it's far more important to choose a manufacturer with a good grasp of the craft and a good reputation, than it is to worry about it after the purchase. Everyone puts out a bad one now and then but a good reputation for quality control goes a long way towards allaying this. In the case of Cold Steel their swords are being carried on the reputation of their knives. A reputation which Cold Steel swords don't live up to.


I know that's the unsettling thing about this case, I did use it for cutting that sort of stuff... no problem. I think you are right about picking a reputable manufacturer though. We again have proof that not all sword makers are created equal...

I guess it shows me once again you get what you pay for. I think I paid 220 for that sword originally.

TRITONWORKS Custom Scabbards
View user's profile Send private message
Keith Larman
Industry Professional



Location: Sunny Southern California
Joined: 21 Aug 2003

Posts: 237

PostPosted: Tue 30 Nov, 2004 1:59 pm    Post subject:         Reply with quote

Oh, to finish my story about the 5160 blade we broke. That blade had been used successfully many times to cut tatami up to about 5 mats thick (which is a pretty good sized target). It was my blade bought years ago to practice foundation polishing. But I had never bothered since when I got it, well, it was so poorly shaped that I decided there were better things to practice on. Anyway, the blade had survived simple and more difficult cutting with aplomb over the years. But I won't cut low on my stand as a matter of habit since I don't like the potential for damaging a sword by clipping the wood stand. After it broke I was *really* glad that I do that. Since I wondered if it would have snapped if it had impacted a stand during a cut... Other times I've seen swords broken due to poor heat treatment they almost always snapped during an unexpected impact with something harder and more "supported" than a mat or soft target. And sometimes it happens after a couple impacts. Not always on the first.

We decided to do the edge to edge stuff with that blade because 5160 has a reputation for being "idiot proof" and very tough. Just goes to show that you should never underestimate an idiot... Wink

Bottom line is that you never know.

There is another related topic fwiw. I've seen some really damaged swords when people take *really* good swords and decide that this means they can abuse the hell out of them. The problem then becomes although the sword itself survives, the mounts fail. So the tougher the blade the more important it becomes that the mounting be up to the task. And all those small details that didn't matter before suddenly become even more important. In Japanese swords that may mean a well-made, work hardened habaki with sufficient "meat" behind the mune to take the abuse. The core being well made and properly fit. Good wraps and rayskin. And so forth. Really they *shouldn't* be abused like that -- a better, tougher blade doesn't mean one should go out and start whacking fenceposts. Because the blade is only part of the equation. It doesn't matter why the blade or part of the blade goes projectile -- either cause is very dangerous.

One other thing I've seen even among experience people is the tendancy to use a damaged blade as a beater blade. Just not a good idea... Yes, it's damaged, so the value is gone, but that means it should end up in the garden as a tomato stake and not as something you go out and whack things with. I've seen a couple blades broken when the owner knew full well the blade was damaged to begin with. They're dangerous enough when they're in good shape...

Keith Larman
http://www.summerchild.com
View user's profile Send private message Send e-mail Visit poster's website
Gary Grzybek




Location: Stillwater N.J.
Joined: 25 Aug 2003

Posts: 559

PostPosted: Tue 30 Nov, 2004 2:43 pm    Post subject:         Reply with quote

Hidden forging flaws can sometimes cause a high end blade to fail. I've seen a broken Raven sword which had snapped at the tang juncture. Some of our expert advisors had a chance to examine the blade and picked out the very spot where it failed. Now, this is no reflection on the sword maker since their reputation stands true. This is just something that periodically happens, even to the best. On low end pieces, failure is obviously going to be more frequent. Testing is a touchy area as we sometimes have difficulty deciding what is abuse and what is acceptable. We can only ask ourselves, what would a period piece encounter in it's lifespan of service? Some can attest to the fact that in our organization, the ARMA, there has been plenty of criticizing in the way we sometimes test our weapons. I agree that some actions although quite extreme may have been encountered during a blades service. For example, a strike to an oponents exposed arm may have been voided or deflected only to make hard contact with his helm. We know that a cutting action is not very effective against such targets but it may have been unavoidable. The sword makers job is to take these likely conditions into consideration and create a weapon that can handle the stresses of battle with minimal chance of failure. Of course, the warriors job is to try and preserve the weapons integrity by use of skill and proper technique. In the heat of battle all of these factors could simply go out the window if it means the warriors survival. Period battle scenes sometimes show us broken blades scattered across the ground so failure, whether abuse or defects in the weapon obviously happened.

Just my thoughts

Gary Grzybek
ARMA Northern N.J.
www.armastudy.org
View user's profile Send private message Visit poster's website
Matt G. Meekma




Location: Horicon, Wi
Joined: 03 Mar 2004

Posts: 61

PostPosted: Tue 30 Nov, 2004 4:03 pm    Post subject: my two cents         Reply with quote

First and Foremost, I am just Glad that the blade broke as Lloyd was doing a back swing instead of swinging inward toward his chest. this allowed the blade to fly free into an unoccupied area. If it had happened the other way around, there is a possibility that it could have hit either Bob, Jason or Myself, event though we were standing well clear of the cutting area a good 20 feet off.

That being said, i will get to my point for posting.

This would have been my third time cutting with the Messer in question. The first would have been the same night that i received the sword. That night Bob and I sent five poor pumpkins to the great beyond with no problems or "signs" that the blade might be flawed or weak in any way.

The second time was at our Harvest Fest at a local fair grounds. There Attempted to cut 2 Grass mats (not tatami) with ok results. The Blade worked fine My technique on the other hand is what prevented a "good" cut. It was also this Day, The Day that the Albion SwordFest took a road trip to our Harvest Fest, That Eric McHugh and Stephen Wittsell From Albion both took a moment to look at the sword in question and get a "feel" of it.

And the Third time I took it out cutting was on the day that it decided that bing two separate pieces was a better thing than being one whole. I took a few, well we will call them practice swings (sounds better than all out misses on the target), before slicing off a side of a pumpkin as can be seen in the photos on Lloyds online album. I put it off to the side to try others blades as well as allow them a chance to use mine as well. Lloyd picked it up, attempted a cut, and the break occurred. We were all astonished at what had happened and we took some photos right away to document it.

At no time during any of the cutting sessions was there any indication that there might have been something wrong with the blade. It just went from Good to Bad in a single swing. Only after it Broke did and we looked at was there any indication that something could have been wrong all along. The Square section at the spine of the blade was much darker and discolored than the rest of the blade and edge. It didn't appear to be an older break, but more of a possible internal flaw.

I have been an Rail Road employee on a local short line for the better part of the last eight years as a maintenance of Way worker and I work around heavy steel and iron every day. While I am in no way comparing Smithing a blade to making rail for RR in terms of skill, there must be, although distant, similarities in the broadest of sense. At any given time a rail can and will, "just" break, due to weather, weight of trains, stress from Machines working on and around it. Sometimes it Breaks from abuse and neglect and other times it breaks due to internal, pre-existing manufacturing flaws.

It is due to the latter of these that each year we hire an outside contractor to x-ray our track as it sits in the ground. I am not too positive that x-ray is the proper term for the process but that is the best term i can think of to use. They have a truck set up to take a constant x-ray as they trave down the rail and if they get a discrepancy of any sort on their monitors they then exit the vehicle and use a hand held unit to closer examine the area and tell not only if there is a problem, but what type of flaw and how serious it is. In this way we are able to correct breaks before they happen and prevent not only costly but dangerous Derailments before they happen. I think this might be the same sort of thing that Both Keith and Chris both had mentioned previously.

I know that the above isn't really more knowledge into the world of swords, but i happen to know much more about Rail than i do about swords right now and I can drawn a comparison between the two.

I guess after all that typing i have just managed to say the same thing that was stated above. You just can't tell, unless you have a really expensive machine.

Beer is God's way of saying He wants Us to be Happy. - Ben Franklin
View user's profile Send private message
Glen A Cleeton




Location: Nipmuc USA
Joined: 21 Aug 2003

Posts: 1,968

PostPosted: Tue 30 Nov, 2004 5:13 pm    Post subject:         Reply with quote

There are a variety of dyes that are used in many industries that show cracks quite well under black lights. The best simple explanatory page I found quicly was here: http://www.sacskyranch.com/crack.htm

I've broken one sword (Hanwei Godfred) and it was a grain issue.
I had sent Hanwei pictures of that and they confirmed an overheat situation. I had cut with this sword for a couple of years before abusing it. This one let go slow when it went, no flying blade.

I don't know how practical dye would be for the average person but one could even use soluble ink and do a wipe.

I check all my edges before cutting and had with the Godfred between cuts while it was failing. That thing just kind of went limp as it ripped across the blade, I finished the tear by hand.

The scary part is that failures seem to be coming unannounced by visual imperfections. Maybe it's time we all look at our blades a bit more closely.

Cheers and be safe

GC
View user's profile Send private message
Steve Ouellette




Location: Fort Collins Colorado
Joined: 23 Jun 2004
Likes: 2 pages

Posts: 23

PostPosted: Tue 30 Nov, 2004 7:08 pm    Post subject: X-Rays         Reply with quote

First, Matt and Russ have answered a lot of questions I wanted to ask on the other post about the Cold Steel Gross Messer failure.
With abuse ruled out I am wondering if the sort of x-ray equipment used to check struct steel welds would work for this. I have a messer and I work for a firm that has a lot of welds checked. I'm going to start looking into getting my sword x-rayed. I wonder how difficult it would be interpreting the x-rays? I wonder what an x-ray of Matt's messer looks like?
I was kind of hoping that Matt had done somthing unreasonable to his messer because I really love mine and hate to think of it failing like that. This might take a while because our steel man travels around and does not work cheap.

In times of peace, the wise gentleman sharpens his sword.
Sun Tzu
View user's profile Send private message Send e-mail
Matt G. Meekma




Location: Horicon, Wi
Joined: 03 Mar 2004

Posts: 61

PostPosted: Tue 30 Nov, 2004 7:54 pm    Post subject:         Reply with quote

Hmmm, Now that i think about it... contractor that we have x-ray our rail is actually here this week doing just that. Think i might throw the blade and hilt into the truck before i trot off to work tomorrow and see if i can't get them to break out the hand held unit on it. Or at the very least get them to explain the process to me a little more in depth. That little bit of knowledge might be of interest. Hope i can find the time for it. When they are around, My department is usually more than a little busy trying to get what they have already found in the tracks fixed or replaced. And let me tell you....they find them way faster than we can fix em.
Beer is God's way of saying He wants Us to be Happy. - Ben Franklin
View user's profile Send private message
Steve Ouellette




Location: Fort Collins Colorado
Joined: 23 Jun 2004
Likes: 2 pages

Posts: 23

PostPosted: Tue 30 Nov, 2004 8:04 pm    Post subject: Woops forgot         Reply with quote

I should have mentioned in my post that I have a messer also. That rail steel is good stuff-a lot closer to sword quality steel than the struct steel I deal with. Keep us posted and my condolences.
In times of peace, the wise gentleman sharpens his sword.
Sun Tzu
View user's profile Send private message Send e-mail
Russ Ellis
Industry Professional




Joined: 20 Aug 2003
Reading list: 42 books

Posts: 2,608

PostPosted: Tue 30 Nov, 2004 8:43 pm    Post subject:         Reply with quote

I would like to further add, that I'm very thankful that no one was hurt. Busted swords can be replaced busted people are a little more of an issue.
TRITONWORKS Custom Scabbards
View user's profile Send private message
Patrick Kelly




Location: Wichita, Kansas
Joined: 17 Aug 2003
Reading list: 42 books

Spotlight topics: 2
Posts: 5,739

PostPosted: Tue 30 Nov, 2004 9:51 pm    Post subject:         Reply with quote

Any good sized auto shop should be able to magna-flux a sword. This process is used in the automotive and aircraft industry to check for cracks in metal parts that aren't visible to the naked eye. I had a rifle receiver put through this process once. It can be expensive though.

I really think we should keep the issue in perspective though. Cold Steel's Gross Mess is generally a cheap piece of crap. Minimal care and attention to detail is put into swords that are produced in this kind of production environment. That these things happen to swords of this quality doesn't surprise me in the least. Let's not get paranoid and fixate on all of the possible disasters waiting to happen in our collections.

"In valor there is hope.".................. Tacitus
View user's profile Send private message AIM Address
Steve Grisetti




Location: Washington DC metro area, USA
Joined: 01 Mar 2004
Likes: 9 pages
Reading list: 28 books

Posts: 1,812

PostPosted: Wed 01 Dec, 2004 6:04 pm    Post subject: Non-Destructive Evaluation         Reply with quote

I am still new at swords and have never attempted any cutting. But, it seems to me that, if you are going to be doing some heavy cutting with a sword, that this is a destructive test of the blade material. Due to the potential consequences of a blade coming apart, even if the probability is low, it seems to me that it would be wise to do some kind of non-destructive evaluation beforehand. I don't care who made the blade - Nobody is perfect. There is a liability question here, too. If we have some attorneys watching this thread, they might care to comment on that.

I work in the power industry, and my firm makes very large rotating equipment (turbines and generators). NDE is not my bag personally, but my firm does a lot of it, because very bad things tend to happen if a turbine blade lets loose at 3600 rpm. We use all of the common techniques that you all have mentioned - Visual Inspection; Dye Penetrant (like the ink method that Glen Cleeton noted - wonder how this cleans up, though); Ultrasonic (I don't think any of you mentioned this?); Magnetic particle (I think this is the same as the magna-flux that Patrick Kelly mentioned); Radiographic (or x-ray, like a couple of you mentioned); and other more exotic stuff. These different tests are good for different things. Visual, DP, and (I think) mag particle are good for surface cracks. I think that, if you really want to know what is going on inside the metal, you need RT - but, the x-rays might not be easy to interpret. Even a good blade will probably show some "acceptable" flaws. A non-homogeneous material, like a damascus blade, might be really tough to evaluate.
UT has its own limitations, but I don't recall what they are right now.

We have some very highly qualified NDE personnel at work. When I get back from vacation next week, I will put out some inquiries as to what might make the most sense in the sword world.
View user's profile Send private message


Display posts from previous:   
Forum Index > Historical Arms Talk > So how do you test a sword
Page 1 of 2 Reply to topic
Go to page 1, 2  Next All times are GMT - 8 Hours

View previous topic :: View next topic
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum






All contents © Copyright 2003-2024 myArmoury.com — All rights reserved
Discussion forums powered by phpBB © The phpBB Group
Switch to the Basic Low-bandwidth Version of the forum