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newbie - treating/tempering 1060


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Hello - My sons and I have been interested in knife making for some time now and we recently took a class on blacksmithing which had the content of forging a knife out of 1060 spring steel. It was a great experience and we want to dive deeper into smithing. We were not able to finish our knives though in the course of a day. We were able to finish our blanks. 

think our remaining steps are to finish shaping on our grinder/sander, heat treat (3 step process? tempering and hardening?) then sharpening polishing, then the handles.

I don't have a forge but I have a pile of coal. From what I'm reading it looks like you can treat 1060 by heating then quenching in water or brine? Is this something I can manage in the backyard?

 

I'm looking at various plans for making a gas forge. My oldest son is going back to college in a week and a half though so was hoping he could finish his knife before then.  Thank you for any guidance.

Edited by Shamus Blargostadt
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Buy the book Introduction to Knifemaking by Steve Sells, offered in the IForgeIron store. It explains knifemaking from the intorduction, to making a knife, to fit and finish, to making a sheath. 

There are several plans for gas forges on the site. You can follow the discussions in the Forges > Gas forges section of the site. Gas Forges

You may want to read the Bladesmithing section of IForgeIron with attention to the Heat Treating Knives, Blades etc area.

Edited by Glenn
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Also you may find there is a bladesmith local to you that could coach or even share equipment.  Have you checked with the Pittsburgh blacksmithing organization: paaba.net ?

 

Is it really 1060 or is it 5160?   I generally use 5160 when I start folks off knifesmithing and quench in warm vegetable oil.  I would advise real chunk charcoal, (NOT Briquettes!), for heat treating a knife and a pile of that and a blow drier can make an effective forge.  I'd say a hole in the ground but your ground may be soggy and or frozen.

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Also you may find there is a bladesmith local to you that could coach or even share equipment.  Have you checked with the Pittsburgh blacksmithing organization: paaba.net ?

 

Is it really 1060 or is it 5160?   I generally use 5160 when I start folks off knifesmithing and quench in warm vegetable oil.  I would advise real chunk charcoal, (NOT Briquettes!), for heat treating a knife and a pile of that and a blow drier can make an effective forge.  I'd say a hole in the ground but your ground may be soggy and or frozen.

​That was what the instructor said it was, trusted he knew. He said it was from the springs from a 19something chevy that he had cut into bars for instruction.

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OK very likely 5160 then which is a common steel for car springs in the last 50 years...Can you contact the instructor and ask?

I'd suggest quenching in warm vegetable oil, (around 140 deg F) and you need a gallon or two depending on the size of the blade.

I'd normalize twice; quench once and temper 3 times. (using vegetable oil should allow you to temper in the kitchen stove without spousal issues)

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yes I'll write him and ask. Assuming you are right about it being 5160 (I apologize for mine ignorance at this stage)

Do I:

- finish shaping and removing steel short of actual sharpening

- heat in a coal fire until it looses magnetism (the knives are about 12" overall length, 1/8" thickest)

- quench in the oil as you described

- Cool completely

- heat in the oven at 400F for 1 hour (from reading other threads)

- quench in the oil

- cool/oven/quench x 3

- sharpen on the grinder, being careful not to heat enough to color

- polish/clean

- done? (aside from handle scales)

Just want to make sure I have it right. Hoping my boys (and myself) will be encouraged by success to really get into smithing. 

Thank you again

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Now you are into basic knifemaking and should read the correct sections on that; BTW you may want to look at a copy of "The Complete Bladesmith" by Hrisoulas as well.

 

I will say:   The edge should still be around the thickness of a dime before heat treat. no you don't requench in oil between tempering sessions.

 

What kind of grinder do you have?  2x72 knifemaker's grinder: yes, Stone grinder or angle grinder: No!

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TP - you were right, he replied back and said it was 5160.  So are my steps above correct (especially the part about heating until it looses magnetism then quenching in warm veg oil) then the oven treating (minus the quenching as you said)?  The Heat Treat app describes a more complicated sequence but perhaps it's the same process and I just don't know it. I sense that screwing up these heating/cooling/machining steps can probably be fatal to the piece. 

At this point the knives are machined to shape and rough scale removed. They are not machined sharp yet (blade edge is still the thickness of a dime or more)

I have a pile of coal and I'm hot on the trail of a break drum to make a coal forge.

Guess I better find me some tongs..

 

Edited by Shamus Blargostadt
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Well you want to be about 130 degF above the curie temp. You will not need to heat it for long to that temp I don't know about your app; but most heat treat info is based on 1" cross sections and if your blade is an inch thick I don't want to talk to you anyway!  

 

Tempering temperature is dependant on what YOU want out of it?  Harder but more brittle?  Softer and tougher?  I'd temper a bowie different from a straight razor!  Just remember you can re-temper at increasing temperatures with no problems; you cannot go down the scale without re-hardening.  The thermal cycling helps; so multiple tempering cycles are advised.

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I sense that you're eager to get going?
In your position I would put the brake drum on hold, make a quick sideblast clay forge and make a first pair of tongs. Then, after getting to know it and if I felt the forge made a good even heat, I'd go ahead and harden the blade. Then you can tinker with sharpening, sheath and handle while contemplating how to design the brake drum forge, or forge some more in the sideblast.

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People use motor oil, but you won't want to temper it in your kitchen oven after you've quenched it in motor oil. I use vegetable oil myself.

I recommend you install, shape, and finish your scales before sharpening the knife. Otherwise you will have to tape the blade while working on the scales, and that can sometimes discolor non-stainless blades.

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Theyre' very different oils. Motor oil is heavier so chills more slowly which if the quench speed were the only consideration could be addressed by how much it's preheated. The real difference though is toxicity, used motor oil is laden with metal grindings and various engine chemicals, anti freeze probably being the most dangerous. This is toxic smoke so you need to do it outdoors in a little bit of a cross wind so eddy currents aren't as likely to collect smoke in your lee.

I took a 5gl. water jug to the local super market and asked if they'd fill it for me next time they changed frier oil. I was hoping to get donut oil but got oil that makes the shop smell like old french fries, burritos and shrimp instead. Oh well, the price was right and it only smells like an old roach coach. The upside is it's not toxic, just makes me smell funny. Being a lighter weight oil and also a heat transfer oil it requires more preheat. check the bladesmithing/heat treat sections here for specifics as to alloy and profile of the tool. Believe me, there's a BIG difference in how you harden a knife than say a turning hammer head. Same process but the details and specific numbers are different.

Whatever you use, make sure you have more than you think you're going to need. The 2.5lb pieces of 4140 for my Little Giant dies all but boiled 5gls. I should've had 2x but it was okay, just not ideal. You also want the quench tank to be deep enough to plunge the entire blade beneath the surface quickly or the oil will flash over and you'll have a fire ball. Swirl the blade so the oil can't develop a layer against the blade and slow the quench.

I preheat my quench tank with a length of 2" rd. stock I heat in the forge and stand in the tank. A meat thermometer is a good way to check to see if the oil is at target temp if you need to be that precise. Just do NOT use the Wife's meat thermometer! No more than you'd use her oven to temper unless you're using fry oil that is.

Frosty The Lucky.

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ok glad I asked. Not a fan of cancer.  That's a great idea, Frosty. Maybe I'll try to hit up the donut shop for oil. Pittsburgher's love their donuts and there are a few places that only make donuts.

I was watching a youtube video by Logan Pearce (https://www.youtube.com/watch?v=_RgwrQXM9jA) and noticed that he appears to only be quenching the edge of the blade (hardening?), rather than the whole knife. Is this common practice? It's at time stamp 2:50 - 3:08 if you don't want to watch through.

 

 

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That'd be differential hardening and the term is about all I really know about it. I'm not a bladesmith guy I only mess with tool steel occasionally. I can do the dance I just don't really hear the music.

Frosty The Lucky.

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  • Use YouTube! Walter Sorrels (a popular American sword/blade smith) has a series on hardening knife steels (O1, D2, 1095,...).
  • You need to know about martensite, austenite, ferrite,...
    My advince: read Metallurgy of Steel for Bladesmiths & Others who Heat Treat
    The pdf above is one of the best manuals on practical metallurgy
  • Forget the steps you need to take (normalize, quench this, temper that) but understand what they are. If you understand them, you will automatically know what to do when. That way you will understand the reasons of warping, scaling, the concept of differential hardening (often used to get a hamon).
  • Use magnets for detecting critical temperature. Never try to get the steel hotter then necessary. This will increase grain growth.
  • Use a metal cannister for the quenching medium and preheat your medium to 60°C. 
  • Google for datasheet 5160. You will get PDF's with scientific information about the steel and how to heat treat, machine, etc. The graphs are very interesting and tell you temper (temperatures,...) to a certain hardness (~HRC, rockwell scale).
  • Read a lot

 

Edited by HDB
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