My first heat treat 1095

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dabidosan

Joined
Apr 17, 2008
Messages
8
Hello All,

I did my first heat treat last night. The blade was ground from 1095 and I used ATF for quench(that is all I had besides cooking oil). I heated it in a one brick forge until it was non magnetic(took about five minutes to get there) and then heated it for another 5- 10 seconds before quenching in 120 degree ATF. After the quench the blade had a "skin" over it that was sloughing off as if it had sunburn and the entire blade was black. I tried to sand it all off but it looks like I have to regrind some of it. the metal now looks half decent and the blade does not look like it was overheated to me but I was just wondering if this was normal or did I do something wrong. Any advice or suggestions would greatly be appreciated.

Thanks,

David
 
Sounds like scale sloughing off the hardened steel. Usually, the color is a dark steely grey after heat treat. It takes careful grinding or sanding to remove it.

--nathan
 
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You likely did not reach full hardness, and a file will NOT tell you if you did. The black, and sloughing is the burned oil coating. Normal! 1095 is not as easy to properly HT as many think. If it doesn't get a few minutes of good soak at 1500o, and get below 900o, in the first second of quench, it ain't gunna be hard enough, and edge holding ability will suffer. 1084 is a much easier steel to work with, when you lack the proper equipment. 1084 is very near the perfect simple steel. Any more carbon requires a specialized quench medium. much less, will not hold an edge as well given the same hardness. 1084 is near the perfect steel for simple HT. It is on the line between hypoeutectoid, and hypereutectoid steel. Steel will only bring .80%, to .85% carbon into solution. Without a controlled soak at 1500o, for a few minutes, 1095 will not disperse it's extra carbon in an even manner, resulting in hard, and soft areas throughout the blade. 1084 will go to full solution quickly, and easily, and hold an edge as good, or better than poorly done 1095, and it is not as picky as to it's quench timeing. Try it, you'll like it!
 
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dabidosan said:
Hello All,

I did my first heat treat last night. The blade was ground from 1095 and I used ATF for quench(that is all I had besides cooking oil). I heated it in a one brick forge until it was non magnetic(took about five minutes to get there) and then heated it for another 5- 10 seconds before quenching in 120 degree ATF. After the quench the blade had a "skin" over it that was sloughing off as if it had sunburn and the entire blade was black. I tried to sand it all off but it looks like I have to regrind some of it. the metal now looks half decent and the blade does not look like it was overheated to me but I was just wondering if this was normal or did I do something wrong. Any advice or suggestions would greatly be appreciated.

Thanks,

David
Click to expand...

Don't forget to temper that blade...
 
Thanks to you all for the info.

LRB - I heard that 1095 was kinda tricky to deal with but that is all they had a Jantz when I did my order. I originally bought some premade blanks and just started adding scales to them. then I got interested in trying to grind my own blades, so I thought I'd throw a few 1095 bars in with my order. I am glad I did, Even though my blade might not be properly heat treated, I did learn a lot during the grinding proccess and I am even more hooked into knifemaking. Now I am looking into purchasing all kinds of tools and spending more money on tools that I can't afford and making room for more tools that I don't have space for. But heck, I can say that I have made a knife right? Anyways, Where can I find a good, reasonable source for 1084. Remember, I live in Hawaii and shipping costs is a B!T$H. Jantz has reasonable shipping costs but does not stock 1084. Anyone have experience with Sheffield? They have it but in 24" lengths and I am not sure how this would affect shipping to Hawaii. They also only have it in 1" in 3/16". I kinda would like it in 1 1/2" for a little wider blade.

MCoughlin - Thanks for the reminder, I'm gonna clean up the blade a bit first and then I plan on doing it in the toaster oven when the ladies are not home. They might have something to say about me cookin a knife. Maybe I could stick in in the pot roast for a little surprise!!!
 
The black color and the scale coming off is not a sign of anything wrong.
As LRB pointed out, you HT leaves plenty to be desired, but others have made good blades from 1095 with less control.
The blade should be tempered as soon as is practical after quench. Wash the blade well with soap and water, then temper the first cycle ( don't worry about the black stuff now). Soak the blade in vinegar overnight, then scrub it with coarse steel wool to clean it up. The blade should be tempered a second cycle then.

Aldo Bruno sells 1084 in the For Sale section of this forum.
http://www.bladeforums.com/forums/showthread.php?t=485280&highlight=1084
http://www.bladeforums.com/forums/showthread.php?t=548789&highlight=1084

Stacy
 
guys, are there any field test to see what hardness has been attained, I'm shooting for over rc60
 
pheo_man said:
guys, are there any field test to see what hardness has been attained, I'm shooting for over rc60
Click to expand...

Oh man, I forsee a whole barrage of replies that will totally disregard modulus of elasticity and penatrative vs. scratch hardness:rolleyes:

I think I will just compromise now... Files! Checking it with a file may be your best bet. :) Files will at least tell you that it cannot be scratched by other hardened steel, instead of pushing the edge on objects to tell what its elastic limit is, which will change with every edge thickness:rolleyes:, but I am sure that won't stop the same old advice from comming. A really good story is hard to let go of. Not that I haven't used a brass rod on my edges, but I preffer to hit the edge instead!:D You see I don't care about the modulus of elasticity, I can find that with a calculator, but impact toughness is good to know;).
 
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I'm confused. Kevin- you talk about the brass rod test as if you expect people to suggest it as a measure of hardness? Something isn't parsing in what I'm reading. I've used the brass rod test to see if an edge can handle a moderate sideways force without damage, knowing that it is dependent on geometry as well as "temper". *shrug*

I recall asking once upon a time about testing without specialized equipment and got a pretty stern lecture on the forum about getting $5000 worth of equipment before even worrying about whether my knives were any good. I'm up to $1400 in equipment now, but I'm still limited to files, brass rods, drop tests, throwing at targets, and chopping wood to test performance. I honestly don't know the RC of any of my blades. (I do know that nicholson files are a lot harder than harbor freight files)

I've been curiuous for a while to figure out a way to test exact hardness, since people ask. do you have a- non lab equipped and relatively cheap- suggestion for testing? rockwell files from knifemaker supply?
 
Koyote, forgive the impatient tone of my last post, but around once a month I get an opportunity to read pearls of wisdom established as reliable in the field and I get a little testy about having sound data and factual information to back certain concepts. My aim is seldom to chastise or attempt to change the minds of folks who are already very happy with what they are doing, my reply was for the benefit of pheo_man since that is where I have decided to concentrate my energies, that is on the guy starting out and looking for sound information, and I feel deserves input based upon facts. I look at it like changing a trajectory or making a course correction. It only takes a very small nudge very early in a trajectory to make a profound change in direction, while if you wait until the course in entirely set and has been traveled for some time it will take a huge effort change the trajectory in any noticeable way.

I hope I was not one of the individuals who gave you a stern lecture, I try not to take that approach, but instead just prefer to put facts out there and allow those interested to pick them up. I myself would not say any specific ammount need to be spent for knives to be up to snuff, some good steel in a well tended campfire is capable of producing a very satfifactory blade even if not always conducive to the smiths mental health. pheo_man’s question did indeed deal specifically with hardness and I must admit that if you are disassociating the brass rod trick with any form of hardness test I would have to give you credit and say that you are perhaps the first person who regularly uses it that has not proposed it is a direct indication of hardness.

I have no problem with anybody using any methods or test they desire, my concern is when bad information is perpetuated by having erroneous facts attached to those methods. The more pheo_mans out there who get accurate facts about these concepts the better our chances of correcting some of that misinformation. Often frugality overcomes our objectivity and allows us to imagine validity that is not always there. $5000:eek: Wilson and Rockwell are not the only ones who make hardness testers. Out in the woods I have pounded nails with rocks to join two pieces of wood- it did work, so one can safely say that a rock can be used for this task. However if I were going to pound nails for a living I would consider the purchase of a hammer in my future.

If, however, you are looking for the quickest and cheapest of hardness checking I would refer back to my previous post where I suggested files. Files at least can measure a form of hardness and get you in the ballpark, and better yet they may give an indication of wear resistance which has a direct correlation to actual knife use, while I don't see a knife use that is a direct parallel to gradually laterally flexing the edge to failure, but then I suffer from the same lack of imagination in finding an association with bending knives in vises:confused:. While one could ask what making little dimple in the steel has to do with actual use, it is a precise measurement of a specific property and not a general test burdened with countless variables.

Once again, if pressed I would at least go with a file.
 
Kevin- nothing to forgive.

I'm actually very confused by the idea that the brass rod test could be a judgement of hardness. I ran across it, of course, in the $50 Knife Shop. But as I read it, Wayne says:

"...I started using it in about 1975 and have found it to be a quick and accurate measurement of edge strength."

Now, being who I am (and having this thing even at the very beginning for convex grinds) I intperpreted this as "edge strength given the steel type, temper, and geometry." Meaning that if you "pass" the test, you've acheived some decent balance of temper and geometry. I just... can't see how this equates to measuring hardness per se.

So I'm completely agreeing with you, I just- it never crossed my mind before that the brass rod test could be a hardness test.

I find myself, constantly, going back and looking at things anew. I'm doing reasonable work with 1084, L6 and 15n20. But I don't know entirely WHY everything works, even if I've got a good cookbook So I look forward to your posts and have a raft of questions saved up for if I ever corner you.

Hardness testing is actually something I'm very little concerned with personally as I've found what I think is a good balance in testing that may not be *really* accurate, but gives me a good grasp on a good blade. I've had blades chip on the drop test, had blades fail under a file after a quench, and I've had blades roll on the brass rod test, and I've broken a few on the throwing range and I know that passing my tests is passing "something".

I'm really just curious about the next step on hardness testing. From the nicholson I go... where? And what does the next advancement of testing tell me? if I get a set of rockwell files, what do they really say? Am i buying a hammer or a screwdriver?

Of course, there's still the question of whether or not I need to do a rockwell test at all. Is it going to improve my knifemaking to know that this blade is 59 and this one is 60?

I'd credit your posts with 3 major improvements in my knifemaking- paying attention to my oil based quenchant, differential tempering instead of edge quenching, and the importance of soaking. So I'm definitely honestly wondering about this. I agree that the file test does something useful, if binary in its granularity.

Oh- lateral stresses on edges are something I am concerned about in choppers and outdoors knives, to some degree. I do think it makes some sense when whacking a piece of wood to know that you'll survive a twisted blow. The bending in a vise thing makes no sense to me except as a traditional measure of tradition. I guess if you can acheive the performance indicated on demand, you have to know something about how to make steel behave. *shrug*
 
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Blade magazine has an article,by Ed Fowler,in the current issue about using Rockwell test files.

As far as the brass rod test, it determines if the blade edge is too hard (chips) or too soft (stays bent).If the edge will flex and return, it is a sign of a proper quench and temper. Since most steel we use will harden to between Rc 62 and Rc 65 on quench, that is the upper reach.With a normal temper between 350F and 450F the hardness will drop to between Rc56 and Rc 60. So if you did at the proper procedures to austenitize the steel,used the right quenchant, and tempered at a suitable temperature......the blade should be about right. The brass rod test is best used to fine tune the temper. Start with a temper a little lower than you think is right. Test the edge. If it chips it needs more temper at a hight temperature.With some experimentation, you should be able to develop a set of procedures for your equipment and methods that will yield a tough and hard blade.With things like the brass rod test, a smith doesn't need to know what the hardness is.....He just knows that it is right.

Kevin is one who needs to know what it is. Most don't. A Wilson tester is great, but won't tell you how the edge will preform.Understanding the metallurgy of the entire blade making process will help you develop a blade that does your desired function. Use/function related testing ( wood chopping for choppers, slicing tests for slicers, impact tests for throwers, etc.....and yes, the brass rod test) will help tell you if you are right.
Stacy
 
Hi David,

I sent you an email, as a fellow blade aspiring Islander, via the BF system. Hope you get it. Sometimes they don't seem to work if settings aren't set right, or something. It'd be nice to get in touch.

Aldo's 1084 will be available late August, but it will be the coveted .25" x 1.5". You might want to check in with Kelly Cupples [octihunter@charter.net] for steel if you can't wait that long. Unfortunately his 1084 is geared more to pattern welding, as it's only .125 x 1.25. He does have other steel though, such as 5160 in the dimensions you're wanting.

Drop me a line. Maybe we could get together sometime?

Aloha, Phil
 
It's pretty difficult to test this stuff without REAL time/temperature control and a few broken blades + hardness tester.

Back when I was more active in persuit of knifemaking as a hobby I tried heat treating a small 1095 wharncliffe blade. It was HT'd with an oxy/mapp gas torch and seemed to come out of the HT/temper performing well, brass rod test checked okay, file skated off of it, using it, it seemed to hold a decent edge etc. I did the HT during dusk to get decent color temp and heated it to a nice bright cherry almost orange red color and kept it there for a minute or two, checked it with a magnet then immediately quenched in hot brine. It was then tempered at 350f for 1 hour 3 times.

After a while I got curious and decided to break it and see what happened. It bent like a wet noodle, only the first 1/4 inch behind the edge was hardened properly and the rest was a real mess as far as grain structure goes. I don't know how to describe technically all the details but it just goes to show that 1095 is not a very forgiving steel when you don't have full control over the heat treating process and some experience with it.
 
Most people overlook the huge difference that materials display in impact rather than in gradual loading, softer steel will exhibit brittle fracture behavior when loaded too quickly for the mechanisms for ductile deformation to occur, thus my point is that gradual flexing of any type won't really indicate how a blade will behave in chopping and why I so often suggest just hitting the brass rod instead. There is no measurement of the exact force applied in the test but one can gauge by eye the amount of deformation which can be increased or decreased simply by grinding off a thousandth or two. So it doesn't measure hardness, it doesn't measure impact toughness and without calculation of stress or strain it really doesn't give useable data about strength from edge to edge, which would give me pause to ask what is the point. But as Stacy pointed out I am a real picky nerd.:o

I must stress that I am cool with whatever folks want to use in their methods, if they are sold on something and it does it for them, what is that to me? But going back to my rock analogy, if the carpenter down the road prefers a rock over a hammer, and can defend it with the fact the hammers cost much more money than rocks thus increasing the profit margin on every nail driven, hey I am infinitely cool with that!:D Why should it bother me that I will have a dozen jobs done with no bent spikes before the competition can drive a several nails?

However when that carpenter resorts to stating that rocks are the equivalent to, or better than, hammers for much less in order to justify the results or drum up work, now a great disservice is being done. New guys wanting to learn carpentry suffer, the consumers suffer, and the craft overall will eventually suffer as truth becomes a casualty to the stone nailing mystique. The rock could be entirely justified by making an artistic statement by its use and selling the results by those merits, but that is not the same thing. The hammer evolved for a reason, it is a specialized tool designed to meet exact needs of the task, to imply that it is was an unnecessary development in order to feel better about rocks would be pure sophistry. With this I don’t mean you Koyote, lord knows this campaign of misinformation goes much wider than this small forum.

This is not intended as a rant of any sort, but an attempt to explain why I seem to insert myself with more passion in some topics than in others. I really wish to clarify my position on what other people use (which I have no position on), and what falsely gets touted as fact in order to justify what people use, which always rubs me the wrong way. It is the reason I just avoid political discussion anymore, ask almost anybody what they think about a candidate or a hot topic and they will give you all kinds of spoon fed talking points and purely emotionally based opinions with no need to know any facts about the subject:rolleyes:. Instead of enduring that I would rather discuss the weather. National politics is such a pandemic that we will never fix the ignorance, but our little corner of the world still has hope if we embrace factual reason wherever we can.
 
Hi Friends,

Well if I want to build a house I think I can afford a hammer, although I have done my share of driving a nail or two in with a rock from time to time. Actually, I haven't acquired nearly all the necessary knowledge and skill sets to build a house. I have built a 16' x16' cabin with loft though. Had a blast doing it too. I must confess, all I had was a hammer though. (I also used infamously inaccurate string levels too.) Got the job done. She's still standing and serviceable as far as I know.

Most folks I know who are real builders use air compressor driven nail guns and sophisticated transits and the like to build. I simply didn't have, nor could afford, them. In fact, it took me a couple of years just to buy the materials a little at a time before getting the job done. Nor was the little building inspected by the proper construction assessing ordinance maintaining authorities. I did consult builder friends from time to time though.

I don't represent it as a pinnacle example of the trade, nor did I not build her because I didn't have all the proper tools, knowledge and skills of the trade. Sure wish I did. Still wish I did. Glad I know folks who do, although sometimes I envy them a little. ;)

Do I sometimes feel foolish in my ignorance? Sure. Do I sometimes feel like I'm walking around with my pants down around my ankles and everybody else knows it, but I don't? Sure. Has it kept me from making knives and exposing my ignorance? Sometimes, especially if I'm going to get hit too hard with hyper-critical advice and admonishments. Do I feel self-conscious swimming at the deep end of the pool with experts and professional? You bet. Am I going to stay in the shade at the side of the pool and just watch? Not all the time any more. I'm going to see if I can slip in at the shallow end without making too many waves so I can make a jaunt over to the deep end from time to time. I'm going to find other intrepid fellow aspirants and hobnob with them in our efforts at hobnobbing with giants.

Not to lose the thread entirely, so am I right in concluding that to assess the quality of your bade...
  • Use known steel
  • Work it with methods, particularly HT ones, appropriate to the steel
  • HT properly, such as: appropriate even (measured) temperatures, soak times, quenching in appropriate medium for the steel, tempering, etc...
  • Evaluate blade quality via Rockwell hardness tester, if you can't then use a file (there are no in between methods)
  • ?
Thank you guys, both "little" and "big." -Phil
 
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Pretty close, you can certainly do it by fire and color, but like any other craft doing it that way takes a whole lot more experience in what works and what doesn't. Because like all good measuring tools, you need to calibrate them for best performance :)
 
You, know I have thought about this all day in the shop and I would like to apologize for being so damned pushy here. I run into writings and information elsewhere when I happen to be tired from a long weekend of doing the firefighter thing, get all cranky and sort of take it out on the good folks here on this forum. I guess my frustration at seeing one side of information with no checks and balances or need for verification just gets the best of me at times. I am now thinking of a more constructive way to take on the information monopoly rather than unloading on you folks. What anybody needs is whatever methods gives them peace of mind and makes the work more enjoyable, and that is what really counts in the end.
 
You do just fine as you are Mr Cashen. Don't stop. I have learned much from your rants, and when you rant, you do them very well.
 
Hey all thanks for the great advice! All started with a question about heat treat and hardening steel and then led to hardening/controlling heat and tempering of the souls. Didn't mean to touch anyones soft spot. Seems like we are all kinda like improperly treated 1095.... hard in some spots and soft in others. I can definitely say that I am not quitting on 1095 yet. After all, did Einstein quit making the light bulb on his first try? Heck everyone thought he was nuts. Did Ben Franklin quit on his first attempt at making the telephone or did Thomas Edison give up on making electricity or did Alexander Graham Bell Discover Hawaii on his first attempt. hahahaha All wrong events with the wrong people(I think) but I think you get the picture. Hehehe, All kidding aside. I have gotten some great info and advice from this forum. Lots of knowledge and great people here.

Stacy - thanks for the info on the 1084. I have been in contact with farmer Phyl and we are trying to get an order together. I have read numerous of your posts here on the forums. Glad to have you here.

Farmer Phyl - Don't you know that you are spelling your name wrong. That could really have a negative impact on some poor kid who could have a shot in the future at being a phylosopher or of studying phisiology and now he can't because you permanently screwed him with spelling! Just kidding! Good news for us Noobs and little people. There only one way to go from here..... and that is "UP". There is a bright side to being at the bottom after all. Great to hear from someone else that uses rocks as tools. After all, That is all I can afford. And besides that, we both live on the same giant rock! Just don't use our "Rock" to pound on some nails. I'll lend you my hammer. I look forward to meeting up with you in the future!

To the rest of you, thanks for all the great info and advice. Even though most of it is kinda over my head right now. I still learned a lot from your advice and will take it to heart when making my next knife. Right now its all about having fun for me and I will just keep my first as is. i don't want to permanently ruin it and kinda want to enjoy playing with this one. Maybe i'll pay for a membership soon so I can start posting pictures of my first couple of blades.

Aloha,

David
 
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