Another question for knife makers

[Ed Fowler]

The Titanic was one of the most publicized incidents of steel failing in cold temperatures it was not designed to experience. One question that may be extremely relevant if you are planning on survival in cold temperatures is: What is the temperature range these blades are suited for?

Knives tested for edge flex and strength at moderate temperatures in our shops can fail in sub-zero temperatures. It is easy to test and adjust the tempering temperature to allow for extreme low temps, but the variable needs to be in your plan.

A blade that is tempered for use at low temps will loose a little edge holding at moderate temperates, but this little cost in edge holding is more than worth it when cold weather use may be in its future.

Knife users can test their own blades by simply putting them in their house hold freezer and testing for edge flex while the blade is still cold. Winter time is the best time to test as you can test outside, cold steel on cold steel.

You can make the test simple by chipping ice, this test can be very revealing.

Your thoughs?

 

[PayetteRucker]

you know it's a good point, how much environmental temperatures affect your blade. Never really thought about it before.

 

[Joezilla]

I had access to a -80 once and used a few 1095 and A2 knives after there without ill effects, but I didn't go crazy with them. In an ancient book called "axemanship", Mason talked about sub zero temperatures and warming an axe near a fire after a cold night. While I haven't had much experience in extreme cold, I wouldn't think twice about sticking it underneath my arm pit for a minute if someone warned me about it when I was up there. I wish I had access to that -80 again. You can bet the ranch I'll be thinking about it and messing around with some blades that I know the temper on. I think it may be getting a little extreme to base a knife purchase on that though. I haven't really heard of the Scandinavians doing it, and they are in some pretty cold areas.

 

[WILLIAM.M]

This question can be answered very well I suppose by people who live in Alaska or Canada...

I would be very interested in Knowing how much of a difference it would make

Great Question Ed!!!

 

[Shotgun]

I read somewhere that when using an axe in cold temps that it's a good idea to stick the head in your armpit for a minute to warm it up. Not sure if this truly has any effect. I would imagine that the blade would cool just as fast but I may be wrong. I don't live in Alaska.

 

[kgd]

I wish I had access to that -80 again.

Really? I can make that happen....Probably not Machete length....but I can make it happen

 

[Ed Fowler]

The question comes to mind - when Randall made the knife for space, What allowances did they make in the temper of the blade? I don't remember reading anything about it.

There was a time when knives, axes, and even rail road rails failed at high rates in cold temperatures. Folks who use chains in extremely cold weather find their strength is greatly reduced, unless they use chains that are developed for use in extreme cold weather. This is something that safety demands we are cognizant of this fact.

 

[WILLIAM.M]

http://www.springerlink.com/content/u92v15747v007054/

ED---CAN YOU UNDERSTAND THIS??

 

[x39]

The Titanic was one of the most publicized incidents of steel failing in cold temperatures it was not designed to experience.

If I remember correctly, the rivets used in the construction of the Titanic were of overall inferior quality, and failed due to a lack of tensile strength. Air temps that night were only around freezing, which should not have had an appreciable effect on the steel. I've worked on vehicles and other equipment at thirty below (F) and have never had a wrench or other hand tool fail, for what ever that's worth.

 

[Ed Fowler]

William - yes I understand, but caution those who rely on chemistry alone, you as the user of a tool or the maker need to test to predict performance. Actual testing is the only way you will know - probably.

x39: The last report I read stated that the materials used were the best available at the time, and that if the water surrounding the ice burg would have been warmer, the Titanic would not have sank. Naturally there are many reports with other conclusions, this is a facet of any tragedy.

When building the Titanic they never considered the possibility of a wreck in cold water.

This is the reason for this thread, when deciding on a tool for survival, you need to consider all the variables how ever remote they may seem. And use those tool in accord to your planning.

 

[Bushman5]

to mimic extreme cold, get 20 lbs of dry ice pellets, and about 5 liters of acetone. Mix the two (acetone does NOT freeze) , stir well and you have a super chilled medium in which to place steel (dont recomend anything with plastic on it.....but blade blanks are fine). Immerse for about 15 minutes and remove (use tongs), then test your lateral strength and chipping tests.

have fun!

oh, if your wondering....i used to use this mixture for supercooling the intake air on my truck during summer driving extremes offroad.

 

[haggismonger]

This is just what I have heard and read in a few places here and there, don't dogpile me. The old ice saws were made of L6 because it held the best properties in lower temperatures, it offered a fair balance between chip resistance and flexibility to do its job. I know nothing of the composition of the steel used in the rivets of the hull plates of the Titanic, although I would suspect that in that period of history, opulence and luxury served as the carrot for many avenues of industry, and with this came the rise of corporate profit margin. Also keep in mind that there were three other ships in the works by the same yard, all setting example and precedent in the level of extravagance. It was deemed more necessary to spend a larger percentage of budget for lipstick and rouge issues. To bring my point back around, and probably in line with Ed's point, I think he may be trying to segue into the delineation between show and go knives. I wholeheartedly agree that there is more to a blade than it's mere composition, the sum of it's parts, but the best qualities of every material and the drawing out of same has been well established by more effective methods than trial and error. I don't think that consideration of construction methods, materials and techniques of shipyards a hundred years ago should carry much weight now, because so much has changed. I think the duty of pushing the limits of steel and redefining boundaries of expectations falls on us as knife makers, because outside the scope of NASA, perhaps, there are few industries that come to mind other than the blade industry that places such demands on it's products.

 

[Rick Marchand]

Very good question, Ed. I regularly train in -20 to -50 temps during the colder months. We shy away from thin blades in those temps, regardless of steel type. NO MACHETES!!! Brittleness in cold was one of the reasons I started making my own knives. I know it depends greatly on the heat treat but I'm not big on high carbon count steels in the bush during winter. (Hypereutectoid, I believe, is what they're refered to as. 1095, 52100, O1, D2...) Unless I see proof of testing, those steels and anything 1/8" or thinner scare the hell out of me in extreme cold. *** Those opinions are arbitrary and reflect my own experiences... they are not backed up by any controlled testing. ***

I chose 5160 and 1070/80 for my bushknives. I don't wear them on the outside of my clothing. When I have a hawk with me, it never stays stuck in a log or tree.

Rick

 

[Mistwalker]

The Titanic was one of the most publicized incidents of steel failing in cold temperatures it was not designed to experience. One question that may be extremely relevant if you are planning on survival in cold temperatures is: What is the temperature range these blades are suited for?

Knives tested for edge flex and strength at moderate temperatures in our shops can fail in sub-zero temperatures. It is easy to test and adjust the tempering temperature to allow for extreme low temps, but the variable needs to be in your plan.

A blade that is tempered for use at low temps will loose a little edge holding at moderate temperates, but this little cost in edge holding is more than worth it when cold weather use may be in its future.

Knife users can test their own blades by simply putting them in their house hold freezer and testing for edge flex while the blade is still cold. Winter time is the best time to test as you can test outside, cold steel on cold steel.

You can make the test simple by chipping ice, this test can be very revealing.

Your thoughs?

From my experiences chipping up or through thick ice is just hard on the edge and tip of any knife. I try not to do that any more unless it serves a real purpose. After snapping One Buck 119 and three Ontario machettes in the winters here I prefer to just keep a knife under some loose clothing when it's not in use in really cold temperatures. However, given the choice, I will say that I'd much rather loose some edge holding ability than snap a blade any day.

 

[udtjim]

I doubt that any of us will have our knives subject to enough cold to see any real difference. I have hunted all over and even in the Dakota's during deer seasons I have hunted in temps from 70 above to 30 below zero. I have left knives outdoors in temps down to 40 below which we get here in the winter. I have never seen any difference in the performance of my knives. In my earlier hunting years, I used almost all Buck knives.

I am not saying that it can't happen but it has to be quite seldom to reach temps cold enough to effect steel. As a kid, we kept an ax in the back of the truck all winter to chop ice on the stock dams so the cattle could drink. Lots of times the ice would be one -two feet thick.

 

[blgoode]

I am lucky in that I have 2 knives now in use by an Alaskan Guide that is out in the bush for up to 8 months at a time. HE ordered the 2nd knife after the 1st trip

Thats about all the testing I can see that is revelant really but I am interested int he results if someone wants to puch teh envelope

 

[kgd]

Interesting Rick, hey next time you have one of them knives that you don't want to let go because 'they don't feel just right' lets test it! I'll bring dry ice!

 

[Rick Marchand]

Interesting Rick, hey next time you have one of them knives that you don't want to let go because 'they don't feel just right' lets test it! I'll bring dry ice!

Sounds like fun.... I have a couple in 5160 and O1...... save some of that ice for the beer!

 

[Gossman Knives]

I am lucky in that I have 2 knives now in use by an Alaskan Guide that is out in the bush for up to 8 months at a time. HE ordered the 2nd knife after the 1st trip

Thats about all the testing I can see that is revelant really but I am interested int he results if someone wants to puch teh envelope

Pretty much the same here Brian. I made two knives for a professioanl outdoorsman who spends months at a time in the bush, Yukon territory. He told me temps are 45 below in the winter months. One of the knives is an 1/8" thick Nessmuk. Both knives are O1.
I have used knives hard on winter camping trips where overnite temps dipped to the single digits.
Scott

 

[kgd]

Okay, putting it back to Ed. There have been a few suggestions about circumventing the field testing environment. Conventional freezers only get to about -20oC, but dry ice as bushman pointed out approaches -80oC. There are also cryofreezers out there like we have at work that will get you to -80 or lower.

So you get your knife cold, now how do you test it? How do you contrast its performance and reference it to normal temperatures? Do you do the bend test until destruction at room temperature and under cold conditions?