MEMBER ITEMS FOR SALE
Custom Knives | Other Knives | General Items
-------------------------------------------
New Posts | New PhotosAll Photos



Go Back   The Knife Network Forums : Knife Making Discussions > Custom Knife Discussion Boards > Knife Making Discussions > The Newbies Arena

The Newbies Arena Are you new to knife making? Here is all the help you will need.

Reply
 
Thread Tools Display Modes
  #1  
Old 09-07-2011, 08:45 PM
DLawson DLawson is offline
Member
 
Join Date: Sep 2011
Location: OK
Posts: 18
Question Heat Treat Question and Testing

I've been lurking long enough I suppose. I finally found a question that I can't find an answer for, so I hope this is the right place to ask.

I finally started to make my own knives. I should say "knife" because I've only completed one so far.

Anyhow, I bought a 3' piece of 1/8 1095 thinking it would be a good steel to start with. Imagine my horror when I was about halfway done and started reading about how finicky 1095 was to heat treat! I felt more than intimidated by what I was reading and everyone's way of heat treating 1095.

Well, by blind luck I suppose my 1st knife came out of HT okay.

I messed my 2nd knife up while grinding, so I figured I'd just go ahead and HT it like I would have done anyway and then put it in a vise to test it to see what would happen.

Here's how I heat treated it. I heated it to a dull red three time and let it cool to black between heatings. The 4th time I stuck it into my makeshift forge until it reached non-magnetic and then quickly quenched it into a gallon of 150 degree ATF.

The first time, it didn't harden so back it went until it was non-magnetic. Quenched again and this time the file skated off the edge! WooHoo!

Then it was into my toaster oven for the temper. 400 degrees for an hour, cool to room temp and back in again at 400 for an hour.

Then I took a MAP gas torch to the spine until blue to try and add just a tad of springiness.

It was late, so I stopped for the night and today I put the knife in my vise and clamped a bar on the end of the blade and started pulling. I got to about 40 degrees before the blade snapped about an inch above where I had it clamped (which was at the ricaso).

The tip was bent good above the break.

Here's a few pics.





Here are my questions:

1. Did I clamp the knife correctly for a destructive test? Or should I have clamped it at the end of the handle?

2. Is this a poor performance for a 1/8" knife?

I still have quite a bit of 1095 left, so I do plan on some more testing with different HT methods. Personally, I think I should have heated the spine up along a longer section.

Looking for suggestions and/or comments.

Thanks everyone,

Don
Reply With Quote
  #2  
Old 09-07-2011, 11:08 PM
Eli Jensen's Avatar
Eli Jensen Eli Jensen is offline
Master
 
Join Date: Jan 2011
Location: Flagstaff, AZ
Posts: 872
My only observation is that it looks like you may have left the edge pretty thick. That may have affected the performance of the test.
Reply With Quote
  #3  
Old 09-07-2011, 11:25 PM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,612
I don't know if it really matters which way the knife is clamped as long as it is the blade section that is bent. If I remember right, the ABS performance test states that the blade is clamped in the vice on the point end 1/3 of it's length up from the point.

As to how hard or easy 1095 is to heat treat depends a lot on the manganese level, from what I've read. I got some from Admiral steel when I started out and it would not harden adiquately in oil; I had to use brine. I was at a hammer-in last summer and ran into Aldo Bruno, the owner of The New Jersey Steel Baron, and he had some 1095 with a higher manganese level that delayed the conversion products of austinite enough to allow good martinsite formation in oil. So not all 1095 is created equal.

The broken end of the blade is a little out of focus but it looks like you have a good fine grain it the steel so that part of your heat treatment is good. It should look like a fine grit sand paper in courseness instead of a course grit.

Cpt-Jens made a good point. If you had sharpened the blade before you broke it you could have tested it for proper hardness post tempering and edge retention.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
  #4  
Old 09-08-2011, 07:26 AM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 484
With 1095, you have much working against you. A file will not tell you how well your HT went. It will only tell you that you did get some martensite formed, but not how much. Non-magnetic is much too low of heat to quench 1095 at. Idealy you want the temp up around 1475?, with a short soak to get a good solution in the steel. Your quench oil, ATF, will not work with 1095, it is to slow in cooling, and 150? is to hot for the oil anyway. 1095 requires a very fast oil to quench. ATF is pretty slow, even heated. To get a perfect quench with 1095, it needs to cool from 1475?, to under 900? in about .8 of one second. No oil will do this, but Parks #50 comes close enough. Your next best oil is canola warmed to about 130?. Bending your blade as a test does not tell you much more than what degree at which it will break, or set bend. You tempered at 400?. If you had gotten a good martensitic conversion in your quench, the blade would be a tad on the brittle side. Think along temper heats of 425? to 450?, if you get a good quench. I don't know where you got your HT info, but you need to do a little more research before wasteing any more steel and time. The file test with 1095 can be a big fooler. The file will skate on poorly hardened 1095, just as well as on well quenched 1095. If the steel did not cool fast enough, you end up with a structure of pearlite mixed with martensite, and the file skates across the martensite clumps never telling you that there is soft pearlite there also.
Reply With Quote
  #5  
Old 09-08-2011, 08:54 AM
Ray Rogers's Avatar
Ray Rogers Ray Rogers is offline
Founding Member / Moderator
 
Join Date: Jun 2002
Location: Wauconda, WA
Posts: 9,840
You didn't mention putting the edge of your blade in water while you torched the spine. If you didn't cool the edge when you torched the spine then the heat probably softened the rest of the blade which is thinner than the spine and thus more easily affected. This would throw off all the rest of your tests.

Since blades tend to taper towards the tip even without a distal taper being intentionally ground the breaking test is done by clamping the tip at least a couple of inches up or 1/3 of the blade length. Bending force is applied to the tang, on larger blades this may require the addition of a pipe for leverage. A full face shield is essential when performing this test ....


__________________

Your question may already have been answered - try the Search button first!






Reply With Quote
  #6  
Old 09-08-2011, 10:10 AM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 484
What is this test supposed to prove or show? Just curious.

Last edited by WBE; 09-08-2011 at 10:16 AM.
Reply With Quote
  #7  
Old 09-08-2011, 11:06 AM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,612
Bending the blade to 90 degrees without breaking is only intended to show that the maker can do differential hardening or tempering to leave a tough but softer spine. It is not a test of the quality of the knife. With differential hardening, as with clay coating or edge quenching, the spine is allowed to cool slowly enough to form pearlite and/or upper bainite. Differential tempering, doing a soft draw, allows more of the carbon to escape solution in the martensite of the spine of the blade to become softer and tougher than the edge of the blade.

Differential tempering cannot convert the martensite in the spine to pearlite unless the steel of the spine is austinized. It would be very difficult to do this without overtempering the edge but it might be able to be done but differential hardening is an easier method of doing this.

Differential hardening can occure automatically with the simple steels, such as 1095, due to it's shallowness of hardening. The blade, with good grain size control, will only harden to twice the depth of penitration. So for arguement, let's say that a certain shallow hardening steel with a certain grain size in the form of a knife blade will harden to 1/16th of an inch. That means that any portion of the blade over 1/8th of an inch will form pearletic steel while parts 1/8th of an inch, or thinner, will form martensitic steel. This does not apply to rods of steel, which will form a martensetic case over a pearletic core.

Breaking the blade is about the only way that we have to check on the grain size control of our heat treating method.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
  #8  
Old 09-08-2011, 11:22 AM
Eli Jensen's Avatar
Eli Jensen Eli Jensen is offline
Master
 
Join Date: Jan 2011
Location: Flagstaff, AZ
Posts: 872
Ray is right, you should have the edge in water when torching the spine. I was doing this just the other day. Also let the blade cool with the edge in the water as well. I made the mistake of torching the blade and taking it out to cool, thinking it would be fine. The heat transfered to the edge and I had to re-HT the two blades I took out to cool.

Also, someone correct me if I'm wrong, but a thinner will lend itself to bending more. Think about foil, there is nothing special about the composition, but it can roll over on itself an infinite amount of times.

Others have made good points. I think the test is a good test and one I plan on trying soon myself. But if successful, the accomplishment is nothing if the same blade does have a sharp edge that holds well. That is why the ABS test tests sharpness and edge holding BEFORE the destructiveness test.
Reply With Quote
  #9  
Old 09-08-2011, 12:49 PM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 484
1095 is one of the worst choices of steel for a maker to use for the ABS testing. Most use 5160 because it is the easiest to make pass the tests.
"Bending the blade to 90 degrees without breaking is only intended to show that the maker can do differential hardening or tempering to leave a tough but softer spine. It is not a test of the quality of the knife."
That statement is much ignored by many.
Reply With Quote
  #10  
Old 09-08-2011, 01:32 PM
DLawson DLawson is offline
Member
 
Join Date: Sep 2011
Location: OK
Posts: 18
Hey, thanks Guys for the suggestions and info. I appreciate you taking the time to help out.

The reason I wanted to test the blade was to see how my heat treating method faired. If I had only bent the blade a little bit and it broke, I would have known that I needed to do something different.

As for my resources, when I was researching how to HT 1095 I just Googled it and there were lots of forum discussions on the subject with a lot of people saying what worked for them and what didn't. It's very confusing to a newbie!

Here are a few of the major places I found info, but by far, it's not all of them!!!

http://www.iforgeiron.com/topic/1272...g-1095-knives/

http://www.bladeforums.com/forums/sh...t-treat-1095-!

After all that reading, I was feeling a bit intimidated to say the least!

I also read The $50 dollar knife shop to get a few ideas. But it wasn't until I read Bob Warner's post from back in 2001 that I decided to start out simple and to experiment.

http://www.knifenetwork.com/forum/ar...hp/t-3285.html

What he said about his blacksmith neighbor saying that Knifemakers make things complicated struck a chord with me. I've known people and Org's in other industries try hard to make something so transparent that they ended up muddying the water.

So I just decided to try and start some place in the middle.

Honestly, I think the blade performed "OK". I don't ever see me abusing a blade like that in real life.

@ Cpt-Jens

Yeah, I didn't think about sharpening it since the edge on my first knife turned out pretty good. The edge thickness was .030.

@ Ray Rodgers and Cpt-Jens

Yes, I had the cutting edge in water while I drew the spine. I also left it in until it had cooled enough to pick up with my bare hands...probably around 10 minutes or so.

As for the grain, it looked very smooth to me. I even used my big lighted magnifying glass and then used another magnifying glass between that one and the knife to look at it. I guess you could call it a Redneck Microscope! It looked very smooth that way as well.

Thanks again for all the suggestion and comments. I really do appreciate them and they have been helpful. Hopefully within a week or so I'll have another chance to try the test again using a different method.

Oh, by the way, my "forge" (if you really want to call it that) consist of a 4" pipe surrounded by the heavy type fire brick. On one side I broke a brick in order to use my Inferno Weed Burner as a heat source. I then use the inside of the pipe as my forge. Get's hot pretty quick, but obviously I don't have a pyrometer to determine the exact temp.

Reply With Quote
  #11  
Old 09-08-2011, 02:48 PM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,612
As for the blacksmith's comment that knifesmiths make things complicated, we have problems that the blacksmith doesn't face. The primary one is heat treatment which one would be heat treatment which can make or ruin a knife. It's also a bit of a broad statement which leaves me not really understanding the comment. Even though a bladesmith is in the broadest sense a blacksmith it's a bit like saying that a cabinet maker is just a carpenter.

The $50 Knife Shop is a great book, as far as it goes, but there are things in it that I don't go along with. One of them is 1095 for beginners but you seem to possibly have survived that piece of advice.

As far as testing goes, the file test is just part of it. You still need to take the blade down to a course edge and see how it stands up. The brass rod test, as described by Wayne Goddard, is not a very good one. You can use a thing brass rod in testing but, instead of trying to deflect the blade and seeing if it chips or perminantly bends, try driving the edge of the blade through it by striking the spine with a wooden or plastic dead blow mallet. It it endents with the edges rolled over a bit then it is too soft and will have to be rehardened and tempered. If the edge chips then you can grind the chips out and retemper a little higher. Increase in 25 degree incriments until you get good results. What you are looking for is the blade to cut into the brass rod with no more that a very slight mark on the edge. You can also use something like bailing wire for the test.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
  #12  
Old 09-08-2011, 04:03 PM
DLawson DLawson is offline
Member
 
Join Date: Sep 2011
Location: OK
Posts: 18
Doug, thanks so much for sharing that bit of info! That seems like a reasonable test for a knife edge and I'll do it on the next knife I finish!

I sit in my garage the other night with my first knife and cut strips of cardboard until I was sick of it (I get bored easily, it was only about 40 or 50 pieces probably). I then tried it out on notebook paper and it would still cut easily. I then cut up the only piece of leather I could find. It was about 1" wide by about 18" to 24" long. I cut it crosswise about every quarter inch or so until I was done. The little knife was a tad duller than when I started, but it would still shave hair.
Reply With Quote
  #13  
Old 09-08-2011, 04:15 PM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 484
Go back and read the post by Kevin Cashen. http://www.bladeforums.com/forums/sh...t-treat-1095-!
Reply With Quote
  #14  
Old 09-08-2011, 04:53 PM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,612
Those cutting tests are great for testing edge retention, which is related to hardness, but it's actually a test of wear resistance. Also every blade should be tested to some degree. Can you immagine what it would be like to cut up cardboard with every knive you make until the edge goes dull? The wire cutting test is quicker because it shows a problem right away. Granted, you should subject test blades to extensive testing, like cutting up boxes but you need to have an easily performed test for every blade. You could also get a hardness tester that measures in HRC or equivalent scales but you're talking of laying out $1K or better for something that will test knives. Most of us have to rely on performance testing.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
Reply

Tags
art, blade, brass, forge, forging, hammer, heat treat, knife, knives, leather, newbie, post, scales, sharpening, tang


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Heat treat question Drache Heat Treating and Metallurgy 10 01-03-2007 03:58 PM
heat treat question Omega Knife Making Discussions 4 12-21-2005 12:05 PM
heat treat question jawpaw Ed Caffrey's Workshop 3 07-18-2002 06:28 PM
Heat treat question s mcfall Knife Making Discussions 7 01-10-2002 11:40 AM
Heat treat question Steve Vanderkolff The Newbies Arena 1 01-02-2002 12:52 PM


All times are GMT -5. The time now is 05:35 PM.




KNIFENETWORK.COM
Copyright © 2000
? CKK Industries, Inc. ? All Rights Reserved
Powered by ...

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
The Knife Network : All Rights Reserved