What is the proper heat treatment method for spring steel?

A

ancientsteels

Joined
Apr 13, 2018
Messages
74
I recently acquired two coil springs from a neighbor of mine that came off the front of some sort of vehicle.
I of course cut them into manageable lengths, but when I make something out of that steel, how should I go about heat treating, hardening, and tempering it?
 
without knowing what it came from it is impossible to say. maybe 5160 or some other steel. stick with a known steel such as 1080 or 1084. even knowing the vehicle it is still iffy as to what it is or what it ain't.
 
Unfortunately I cant buy proper steel, so I use what I can get. I think it is 5160, and assuming it is, are there any pointers on heat treatment?
 
Have you read the stickies? There's a bunch of good info there, including heat treating info.
 
If you go back one step from here into the main list of threads in the "Bladesmith Questions and Answers" you will see a yellow colored section at the top of the list of threads. These are topics or information that are particularly valuable and worth preserving. These are kept easily accessible by sticking them in place at the top of the list where they won't disappear.
 
It is probably an alloy similar to 5160. Use the HT parameters for 5160/9260 and you have your best guess at HT.

It would help a bit if you told us what car/truck make and year it came off of.
 
ancientsteels said:
Unfortunately I cant buy proper steel, so I use what I can get.
Click to expand...

I find this hard to believe. Steel is very cheap and a stick of 1/8” thick 1085 that’s 1.5” wide and almost 12” long is only $5. I big coil spring is not somthing most people starting out are set up to handle. Plus most of those coil springs are not large enough to really forge out into anything practical unless you have a good amount of forging experance under your belt and the proper tools to work it. I’m guessing you don’t have the proper tools or the knowledge base to deal with a coil spring. Only reason I say that is becaus if you did, you would not be here asking. I’m not knocking you, I’m just trying to point you in the right direction. Trust me when I say start with somthing easier. A nice flat bar of 1085 steel is easy to work with. Does not need any forging and you can make a knife with very basic tools. That is a lot more fun then spending a week beating on a coil of steel and trying to draw it out wide enough for a blade. You will spend more then the cost of the 1085 in fuel to heat the spring so you can forge it out.
 
Another case of the need for full filling out of profile so we can know what part of the world the OP is at. There are plenty of places in the world where it's hard and expensive to buy good knifemaking steel. OP - please fill out your profile, it will help LOTS in determining a good answer for you.
 
i4Marc said:
If you go back one step from here into the main list of threads in the "Bladesmith Questions and Answers" you will see a yellow colored section at the top of the list of threads. These are topics or information that are particularly valuable and worth preserving. These are kept easily accessible by sticking them in place at the top of the list where they won't disappear.
Click to expand...

Ok Thanks
 
Stacy E. Apelt - Bladesmith said:
It is probably an alloy similar to 5160. Use the HT parameters for 5160/9260 and you have your best guess at HT.

It would help a bit if you told us what car/truck make and year it came off of.
Click to expand...

Ok thanks for the tip. Unfortunately I don't know what vehicle, model or year, it came off of, but it is a fairly good diameter, about half inch.
 
JTknives said:
I find this hard to believe. Steel is very cheap and a stick of 1/8” thick 1085 that’s 1.5” wide and almost 12” long is only $5. I big coil spring is not somthing most people starting out are set up to handle. Plus most of those coil springs are not large enough to really forge out into anything practical unless you have a good amount of forging experance under your belt and the proper tools to work it. I’m guessing you don’t have the proper tools or the knowledge base to deal with a coil spring. Only reason I say that is becaus if you did, you would not be here asking. I’m not knocking you, I’m just trying to point you in the right direction. Trust me when I say start with somthing easier. A nice flat bar of 1085 steel is easy to work with. Does not need any forging and you can make a knife with very basic tools. That is a lot more fun then spending a week beating on a coil of steel and trying to draw it out wide enough for a blade. You will spend more then the cost of the 1085 in fuel to heat the spring so you can forge it out.
Click to expand...
Where I live I am approx. 2 hours from any city, and for the dimensions you are talking about its about $12 - $20 (I checked prices), not to mention the price of gas which is almost $4 a gallon, and it takes 5 gallons one way to any major city with a steel yard. Total cost for me would be almost $50 for what you are talking about, which is money I don't have. I don't even have $5 to my name, because Jobs are scarce and I live so far out (and yes I have been on the hunt for jobs), and have VERY little transportation. The only way for me to move would be to abandon all of my possessions and live in a homeless shelter, or on the street. As it is I have no idea how I am going to pay next months phone bill (also internet source). So I don't even have two pennies to rub together.
So I get scrap steel from a friend of mine. Axle shafts, large coil springs, railroad spikes he gets off of a friend of his who works for the rail road, and anything else that has any reasonable carbon content.
 
Ken H> said:
Another case of the need for full filling out of profile so we can know what part of the world the OP is at. There are plenty of places in the world where it's hard and expensive to buy good knifemaking steel. OP - please fill out your profile, it will help LOTS in determining a good answer for you.
Click to expand...
I have just finished filling out my profile to the best of my ability. Thanks for the feedback.
 
ancientsteels said:
Where I live I am approx. 2 hours from any city, and for the dimensions you are talking about its about $12 - $20 (I checked prices), not to mention the price of gas which is almost $4 a gallon, and it takes 5 gallons one way to any major city with a steel yard. Total cost for me would be almost $50 for what you are talking about, which is money I don't have. I don't even have $5 to my name, because Jobs are scarce and I live so far out (and yes I have been on the hunt for jobs), and have VERY little transportation. The only way for me to move would be to abandon all of my possessions and live in a homeless shelter, or on the street. As it is I have no idea how I am going to pay next months phone bill (also internet source). So I don't even have two pennies to rub together.
So I get scrap steel from a friend of mine. Axle shafts, large coil springs, railroad spikes he gets off of a friend of his who works for the rail road, and anything else that has any reasonable carbon content.
Click to expand...

I find your response kinda disturbing. I fully understand being hard up, we have all been there. Except maybe Stacy, I think he is surrounded by gold and gem stones. Any way, if you fill out your profile and let us know the general area and what state your in you might be surprised with the knife makers in your area. Many of us like helping people get started into this craft.

But all that aside I feal concerned for you in that you are flat broke and don’t even know where rent or phone bill money is coming from. Like I said we don’t know the area your in or how the economy is. but personally if it was me I would not be picking up a new hobby at this time. I would be doing anything I could to solve the current problem at hand. But like I said that’s me and we dont know much about you.

I know you did not come here and start this post to get advise on financial issues. But you went into quite a lot of detail about your situation. Generally speaking we are a very honest group and try and help when ever we can.

All that above being said and done I ment get the steel online. There are a handful of places that sell that steel for $5 and then thy ship it right to you. If your spring is only 1/2” diameter then you will be quite limited on what you can forge with it. As you forge it down it’s going to widen and lengthen. I’m guessing that you would end up with around a 3/4” wide bar that’s around 1/8” thick by the time your done. That’s not saying there are not ways to over come the small diameter. But it requires a bit of skill and proper technique. It’s called upsetting, and it’s where the steel is heated and forged back down into its self from the end. This causes the diameter to expand and the bar gets shorter. What do you have for a heat sorce to heat the steal. You want to be able to hit the 1800-2000° range
 
JTknives said:
I find your response kinda disturbing. I fully understand being hard up, we have all been there. Except maybe Stacy, I think he is surrounded by gold and gem stones. Any way, if you fill out your profile and let us know the general area and what state your in you might be surprised with the knife makers in your area. Many of us like helping people get started into this craft.

But all that aside I feal concerned for you in that you are flat broke and don’t even know where rent or phone bill money is coming from. Like I said we don’t know the area your in or how the economy is. but personally if it was me I would not be picking up a new hobby at this time. I would be doing anything I could to solve the current problem at hand. But like I said that’s me and we dont know much about you.

I know you did not come here and start this post to get advise on financial issues. But you went into quite a lot of detail about your situation. Generally speaking we are a very honest group and try and help when ever we can.

All that above being said and done I ment get the steel online. There are a handful of places that sell that steel for $5 and then thy ship it right to you. If your spring is only 1/2” diameter then you will be quite limited on what you can forge with it. As you forge it down it’s going to widen and lengthen. I’m guessing that you would end up with around a 3/4” wide bar that’s around 1/8” thick by the time your done. That’s not saying there are not ways to over come the small diameter. But it requires a bit of skill and proper technique. It’s called upsetting, and it’s where the steel is heated and forged back down into its self from the end. This causes the diameter to expand and the bar gets shorter. What do you have for a heat sorce to heat the steal. You want to be able to hit the 1800-2000° range
Click to expand...


I tried on line too, and shipping cost nixes the deal.
I've tried steel producers, E-bay, and many others. Ill try to be more specific on my profile, but its kinda hard unless I give Latitude and Longitude, Suffice it to say I live 10 miles from Ash Fork Arizona on roads straight from H*LL. the only thing that can make it in and out to the big city are my room mates trucks, and we only make 2 trips at most to any big city. As Fork has NO jobs to offer, and if they did I cant get to them any way, because of roads, and I (at 21) only have a learners permit thanks to being screwed over by my parents. I have no GED, or High school diploma either (again from being screwed over by parents) which makes it even harder to find a job. fortunately my room mate doesn't have to pay rent (land is payed off) and doesn't ask me for any rent. But i have a bunch of hurdles to over come, and I am being face with the possibility that I might have to leave here any way and go to a homeless shelter just to get a job, because my room mate cant support me, and its not their job to do so any way. After all I am 21 and should be able to stand on my own (theoretically). But my life has been one s$%t storm after another, and none of them my doing. Blacksmithing isn't a hobby for me, I am trying to make something from nothing with it, if at all possible. One day I hope to have a shop and sell my work, but at this point that is a long way off. I have sent an application to a job else where, but don't know if the owner will be willing to give me the benefit of the doubt, or have any where for me to stay. Like I said I don't have two pennies to rub together.
I am basically up s@$t creek with out a paddle.

I can easily reach 1800 degrees in my forge even with out bellows, it drafts that well. I stumbled on a lucky combination with it, and use wood for the fire.
I appreciate the feed back. We all gotta stick together.
 
ancientsteels said:
Unfortunately I cant buy proper steel, so I use what I can get. I think it is 5160, and assuming it is, are there any pointers on heat treatment?
Click to expand...

May I respectfully suggest using your favourite search engine.
Just for the moment assume you know that you have 1080.
Search "1080 steel properties" in the search engine,
and you will find somebody listing the element content eg .50% carbon, 8% chromium etc,
and very often on the same site (sometimes the same page) heat treatment temperatures are given
e.g. heat to 1250 degrees C and hold for 10 minutes per inch diameter, quench in oil at 100 C,
temper at 650 C.

Lots of info out there given freely by steel manufacturers and stock holders.

As for the steel itself! Unless it is a 'super steel' basics! ie heat to non-magnetic,
quench, clean to shiney with sand paper, pop into the kitchen oven at 200 C
until it changes colour to, say, light straw (hard enough to keep an edge)
or dark straw (not quite so good at keeping a sharp edge - but tougher)
down to blue (very tough - odly most springs are tempered to blue for toughness).
Some steels have specific temperatures or will not harden or temper properly,
but this info' is available by searching for (if known) that steel.
Otherwise the carbon content is a useful guide (spark test?) or sacrifice
a small test piece and harden and temper until you get the results you need
by trial and error.


Colour charts available from your fav' search engine.

Hope this helps.
 
AncientSteel: You are correct, the cost of ordering steel online isn't the cost of the steel, it's the cost of shipping. If you're a big knifemaker who orders several hundred dollars of steel at a time, the shipping can double or triple the cost of a 3 ft piece of steel.

This issue of using "found/mystery steel" has been hashed out many times on many different forums. Car spring steel is considered to be one of the better "mystery" steels around. Regardless of make or model you can forge it to a flat bar. You 1/2" round bar might not make a 2" wide bowie blade, but it will make a nice blade shape. You can heat treat by heating just past non-magnetic, quenching in canola oil (best to heat canola oil to 120F before quench). Then temper for a couple hrs. While this won't give a blade of known alloy, nor expect it to be the equal of 80CRV2 steel that is properly heat treated, it will make a serviceable knife.

Good luck and have fun. BTW, what type of forge are you using?
Ken H
 
Just spit balling. If you had a old file laying around it might be something to play with. Not the best thing bit at least it's the right shape. If it seems like you have free fuel and lots of time you could pretty much mess around with just about anything. If you get to the point you can forge weld you will have all kinds of options. All that hammering should be great stress relief too.

If it helps I know how trapped feeling growing up without a lot of education and in a rural area can make you feel. Keep in trying let us know how it goes.
 
stickwhistler said:
May I respectfully suggest using your favourite search engine.
Just for the moment assume you know that you have 1080.
Search "1080 steel properties" in the search engine,
and you will find somebody listing the element content eg .50% carbon, 8% chromium etc,
and very often on the same site (sometimes the same page) heat treatment temperatures are given
e.g. heat to 1250 degrees C and hold for 10 minutes per inch diameter, quench in oil at 100 C,
temper at 650 C.

Lots of info out there given freely by steel manufacturers and stock holders.

As for the steel itself! Unless it is a 'super steel' basics! ie heat to non-magnetic,
quench, clean to shiney with sand paper, pop into the kitchen oven at 200 C
until it changes colour to, say, light straw (hard enough to keep an edge)
or dark straw (not quite so good at keeping a sharp edge - but tougher)
down to blue (very tough - odly most springs are tempered to blue for toughness).
Some steels have specific temperatures or will not harden or temper properly,
but this info' is available by searching for (if known) that steel.
Otherwise the carbon content is a useful guide (spark test?) or sacrifice
a small test piece and harden and temper until you get the results you need
by trial and error.


Colour charts available from your fav' search engine.

Hope this helps.
Click to expand...
Cool. Thanks for the tip, I will definitely do a spark test, and probably sacrifice a small piece of steel to test HT purposes. Thanks for the feed back!
 
Ken H> said:
AncientSteel: You are correct, the cost of ordering steel online isn't the cost of the steel, it's the cost of shipping. If you're a big knifemaker who orders several hundred dollars of steel at a time, the shipping can double or triple the cost of a 3 ft piece of steel.

This issue of using "found/mystery steel" has been hashed out many times on many different forums. Car spring steel is considered to be one of the better "mystery" steels around. Regardless of make or model you can forge it to a flat bar. You 1/2" round bar might not make a 2" wide bowie blade, but it will make a nice blade shape. You can heat treat by heating just past non-magnetic, quenching in canola oil (best to heat canola oil to 120F before quench). Then temper for a couple hrs. While this won't give a blade of known alloy, nor expect it to be the equal of 80CRV2 steel that is properly heat treated, it will make a serviceable knife.

Good luck and have fun. BTW, what type of forge are you using?
Ken H
Click to expand...

Thanks for the info. Ill give it a try.
I custom made (not pretty but it works) a forge out of an 80 gallon (33 inch long) RV propane tank. Oxy Gas cut the door and the hole for the smoke stack, for which I used 3 16inch long pieces of 6inch stove pipe. made a door for the front of the forge out of the piece of steel I cut out to make the door hole. I pile a 2 inch layer of old charcoal on the bottom, put a pile of kindling on top of that, light a fire, stack any large wood I can find on top of that once I have a good fire going, wait a half hour or so until all is a nice bed of bright coals, put on a little more wood to keep a flame going, and the draft keeps the first 16 inches from the door back at about 1800 degrees, hot enough to get a 1 inch X 14 inch piece of steel to a nice bright orange. Hot enough to work the steel without causing stress fractures or other unwanted blemishes from occurring during hammering. I would post a pic of it but I cant figure out how to upload a picture on here. I have actually made the mistake of burning through a piece of steel by leaving it in the fire too long, and thats with out a bellows.
 
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