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Greg Agresta

Steel Question

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So far I've been making knifes out of steel purchased online. Now that we've got our shop ready to go I'd like to try my hand at forging a knife from a simple piece of steel, not something I've bought. I do have some railroad spikes but I'm looking for other kinds of steel that's forgiving since I'm new at this. Any suggestions??

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Do you mean like crowbars, springs,  garden shear kind of stuff? Springs are your best bet.

Im working on a blade made from a shovel blade with a baseball bat handle for the handle.

Look for things that need to be wear resistant, things that are already blades, and things that have to bend back and forth or resist bending. 

If you cant successfully heat treat it with simple techniques it probably isnt worth your time. However, if you manage to find a few hundred pounds of scrap bandsaw blades or wear plates or something it could be worth digging in a little deeper. But there is plenty of steel out there that wont make a knife to todays standards.

If you do make a knife out of recycled material you should test it against a knife thats made of "knife steel", I get some satisfaction from making nice things out of junk but they still have to preform well.

Do not use any metal with any kind of coating! If it has a coating dont try to grind it off, its not worth hurting yourself by breathing in horrible dust or fumes.

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Posted (edited)
22 hours ago, Greg Agresta said:

So far I've been making knifes out of steel purchased online. Now that we've got our shop ready to go I'd like to try my hand at forging a knife from a simple piece of steel, not something I've bought. I do have some railroad spikes but I'm looking for other kinds of steel that's forgiving since I'm new at this. Any suggestions??

I take it you have been using known steel and making knives by stock removal? Now you want to try forging to shape and don't want to use the expensive stuff while you learn the basics of moving steel under the hammer? If this is incorrect, please feel free to ignore everything that follows. If I am correct, please consider this:

There are only a few basic forging operations you need to know to start forging blades: Tapering, drawing, fullering, and beveling (spreading). All of these are used to create a multitude of useful objects like coat hooks, pot racks, chisels, punches, towel bars, TP holders, and the list goes on and on. Most blacksmiths learn these smithing basics on mild steel and produce useful things for their house, shop or to sell and raise money for more supplies and stuff. (lots of stuff). First off, I suggest you buy a book on basic blacksmith work. The Skills of a Blacksmith Vol 1 by Mark Aspery or The Backyard Blacksmith by Lorelei Sims are both very good for the beginning smith. Start by making the same item over and over again, using mild steel or any piece of scrap whatever you have lying about. In the end, it will make you a bunch of stuff that you can use, rather than a bunch of KSOs that you toss in the graveyard of broken dreams. It's important to have a specific goal in mind when you forge. The size, shape and proportions should be known well in advance of lighting the forge. I look at the posts of beginners who start right off trying to forge a blade with no ability to shape the steel in the fashion or direction they want, and it shows in the finished product. Good efforts that probably would have been great ones, if they had made a dozen or two coat hooks first.

Forging is about imposing your will upon the steel. It is about focusing your intent and making what you intend. Visualize, define, forge. In that order.

Everything you need to know about forging a knife is learned by taking a short piece of 1/2" round stock and making this.

hook.jpg

Edited by Joshua States

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What he said^^. 

I get to do ornamental work from time to Time. Repetition really helps teach you the little things. Simple tapers on hooks or scrolls, bottle openers, or whatever. The railroad spikes would be great for all these. Look up some ideas online. 

When I started out I messed with railroad spike tomahawks a lot (mostly messing up). This is really good practice because there's hardly enough steel there to do what you need it to. Also, it involves a lot of useful processes like upsetting, punching/slitting, drifting, using the cross peen to draw the metal in one direction, and finally beveling. But, that might be a good intermediary challenge for you. 

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I also suggest using mild steel to learn the process.  it's not hard to find, rather cheap, and comes in about any dimension you want from wherever you might find it.

Trying to find usable scrap steels is like treasure hunting.  You may or may not find a usable alloy.  Even if you do find a usable alloy, once forged, it's quality is less than a new steel of the same alloy.   I do use it 'scrap', but that's only because it's available and cost me nothing for my own tooling as of right now.  

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One option I can suggest is leaf springs, hit up a wrecking yard and get a bundle, that is PLENTY of steel to play with. And will probably cost you less then a bar of good steel to get.

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2 hours ago, Daniel W said:

  Even if you do find a usable alloy, once forged, it's quality is less than a new steel of the same alloy.   

Forging has nothing to do with it. The steel wont be good if it has stress fractures. But otherwise, it wouldnt matter if its used or new, 5160 would be 5160.

However, ive never seen anyone actually say they had a blade fail because of stress fractures as far as I can remember.

I think of good scrap steel as treasure, not because its hard to find, but because its easy to find and quite capable.

I think this used steel hate has something to do with the noobie super steel mentality. Make a knife, see if it works, thats what matters, not some name. Name it knife steel if people have a problem with unknown steel. 

What good is knowing a pepper is spicy if you still have to eat it to understand it?

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Part of the bad rep recycled steel has are questions like "I forged a knife from a dohicky off a 1932 whatsit.  Can anybody tell me how to heat treat it?"  I think that you'd be hard pressed to find anyone who was around in 1932 or know what that person was talking about.

Steve's right about about stress fractures in used steels.  It's a craps shoot.  I'm quite sure that the leaf springs in my Rav4 were made of a steel that would also make good knife blades but after 200,000+ miles I would hate to think what condition they'r in.  Plus you can't necessarily assume that each leaf in the bundle is of the same alloy let alone from vehicle to vehicle.

Doug

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Yeah, it's basically about heat treatment.  If you don't know the alloy you can't heat treat it for the best performance.  You can experiment to find a way that works okay, but you'll never know if it could have been better.  "Good enough" is not good enough for a knife with my name on it. You may not care. I do, so I use known steels.  Note this includes new leaf springs.  And old files.  On those we may not know the exact alloy, but we do know the heat treatment is similar enough for the alloys they may be to be interchangeable.

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On 5/30/2019 at 10:52 AM, steven smith said:

I think of good scrap steel as treasure, not because its hard to find, but because its easy to find and quite capable.

I think this used steel hate has something to do with the noobie super steel mentality. Make a knife, see if it works, thats what matters, not some name. Name it knife steel if people have a problem with unknown steel.

Yay! I love using scrap tool steel for stuff and I used lots of it in my early days just to get used to how forging tool steel differs from forging mild. I always took a small piece off the bar and played with the HT to see how it worked and figure out what didn't. 

 

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I should be clear that I do use scrap for all sorts of stuff.  It will teach you a lot about how different alloys move or not, as the case may be.  I just don't use it for knives.

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It has occurred to me on a number of occasions, that many of the smiths whose work I admire use "mystery steel" in their blades all the time and we often praise them for doing so. After all, what is that stuff that folks are cooking up in their back yard in those smelters or in those little crucibles? It certainly isn't a homogenous alloy. It's bloomery, and quite possibly, of unknown composition. Unless of course, they have each bloom and biscuit sent out for analysis.

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Posted (edited)
On 5/30/2019 at 1:52 PM, steven smith said:

I think this used steel hate has something to do with the noobie super steel mentality

I can't speak for other smiths, but in my case, it's time, effort, and return.  The price of new steel is insignificant compared to the time and effort I put into my work.  Plus, as is everything I have or use in my business, I can pick up the phone or use the internet to order what I want, any time I want. 

Edited by Gerald Boggs
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3 hours ago, Joshua States said:

It has occurred to me on a number of occasions, that many of the smiths whose work I admire use "mystery steel" in their blades all the time and we often praise them for doing so. After all, what is that stuff that folks are cooking up in their back yard in those smelters or in those little crucibles? It certainly isn't a homogenous alloy. It's bloomery, and quite possibly, of unknown composition. Unless of course, they have each bloom and biscuit sent out for analysis.

Ah, but that is another beast entirely!  And it is also where experience with unknown steels helps immensely.  When you make your own steel, you become the metallurgist.  With smelted steel from ore you can usually find out the ore composition from your state geological survey.  You can count on low manganese unless your ore is from a mixed bank (the manganese is usually under the iron bed, and the two seldom mix in a single rock), and even then it is difficult to get the two to combine in a smelt due to different smelting conditions required for each.  The only thing you have to watch for is phosphorus, and high-P ore is not that common.  And you'll know you have high-P bloom as soon as you try to forge it.  You will not get chromium, nickel, or copper.  Even the gossan ore from the Copper Basin in southeast TN was segregated from the copper despite forming as a cap atop the copper body.  You won't get sulfur as long as you stick with charcoal for the fuel.  Even with titaniferous magnetite you will lose the titanium to slag (often freezing up the furnace in the process, Ti slag is thick and gooey and freezes at a higher temperature than iron slag).  In other words, you can count on it being an almost pure iron/carbon alloy unless you're using high-P ore.  

Hearth steel is a bit different, as you can add modern alloys to the melt.  Emiliano's work in that area seems to indicate you can even count on losing much of the carbide-formers during the melt.

Crucible steel is another thing entirely, and I don't know enough about it to offer meaningful commentary.

But yes, homemade steel is an exercise in estimating carbon content and finding the best heat treatment for the steel at hand.  You often have to water-quench from a higher temperature than you'd expect to get good hardening because it's so shallow-hardening.  

The short version of all the above is it pays to have a lot of experience with unknown steel if you're going to try homemade stuff.  This is a lot different than trying to get that experience without having first gained knowledge of known alloys to smooth the extremely steep learning curve.  It's a lot like playing with old wrought iron.  We all know that wrought does not improve a blade no matter what you do to it.  Those of us who use it, and who dabble in homemade steels, understand it is not a superior material in any way.  We do it for historical purposes and because it's just so darned cool to be able to say "I made that from a pile of rocks."  In that case, the customer knows what he or she is getting.  That is different from saying "I made that knife from an old bed rail that seemed to be high carbon steel."

I know I seem to be waffling on the subject, and I apologize.  It comes down to my personal opinion that new makers are best served by learning on known alloys before they branch out into the hard stuff.  Once you know what you're doing, then you can experiment on toilet snakes and hearth steel made from bottle caps.  I know I have been humbled by wrought iron more than once, and it will happen again.  By all means, do what you want.  Just be honest with yourself and your customers.

Plus it's easier for me to help troubleshoot if I know what steel you used...;)

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Posted (edited)

Ahhh, Sir Longmire. You are so eloquent in your discussion. Well put sir!

And Mr. Boggs. You are so darned practical!

Edited by Joshua States

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Posted (edited)
On 5/30/2019 at 10:56 AM, Daniel W said:

  Even if you do find a usable alloy, once forged, it's quality is less than a new steel of the same alloy. 

I've been working under the impression that every time a piece of steel is forged or even heated to forge temperatures, it is degraded.  However minor that may be. 

I have no hate for used steels, nor do I believe anyone trying to get a good start would. Every tool I have to make is from scrap.  And it comes with the price of time invested in testing the steel before I even start to use it to ensure that it is serviceable for what I need it for.   For the time being, using scrap is good enough for me and my projects I make for myself.  However if I want to make something better as my skills and confidence grow, I'm truing to new known steels. 

 

Edited by Daniel W

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13 hours ago, Daniel W said:

I've been working under the impression that every time a piece of steel is forged or even heated to forge temperatures, it is degraded.  However minor that may be. 

That is not a correct impression.  You have the ability to degrade it, but you can also make it better.

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I would also like to add that a blade does not bear the mark of every hammer blow that it receives.  Every time the iron matrix in the steel passes from a body centered cube to a face centered cube and back the atomic bonds between the iron atoms reform.

Doug

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Not sure if my interpretation is correct, but when etching blades, some forged from a Nicholson file and some stock removal from the same, the steel in the forged blade seems more even after the etch.

 

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On 6/3/2019 at 7:09 PM, Daniel W said:

I've been working under the impression that every time a piece of steel is forged or even heated to forge temperatures, it is degraded.  However minor that may be. 

 

I think this might have just a pinch of truth if you consider decarb. But just the smallest of pinches and you can and usually do grind past it. When you work a steel and develop cracking along a weak spot, it may seem like it was the steel's degredation, but its actually operator error. How many times did you hit it too cold, or overheat, or bend it back and forth? Like Doug said, those atoms are resetting every heat. 

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I was thinking along the lines of de-carbonizing steels. My thoughts on the subject were always that the next heat, continues to degrade the steel deeper and deeper.  Therefore to get as much forged as possible in as few heats as possible. 

I realize I do not have enough experience with using salvage carbon steels, and new carbon steels to give an accurate statement as I did in the beginning.  In regards to that I need to get to work a little (much) more often.

 

 

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While this main focus of this is on blade suitable steels, I'd like to give a couple of examples of new steel prices:

My last purchase of mild 1/2 round, 200 feet was $103.  That's 51.5 cents a foot.  Or about 35 cents a pound?

4140, 3/4 round, 12 feet was $19.  This price always various, as low as $15 to as high as $22

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On 6/4/2019 at 11:13 PM, Doug Lester said:

I would also like to add that a blade does not bear the mark of every hammer blow that it receives.  Every time the iron matrix in the steel passes from a body centered cube to a face centered cube and back the atomic bonds between the iron atoms reform.

Doug

you obliviously did not get to see my early work every hammer mark was visible when done :unsure:

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