Jump to content

Coil spring question


J Logan

Recommended Posts

I'm not new to smithing but I had an accident a few years ago that took one of my arms out of commission for about a year and now I'm ready to light my forge again and see if I can do this. The only steel I have at the moment is two rusty, pitted leaf springs and a single coil spring that I picked up after it was thrown out of a truck during a head on collision. I know these springs are not trustworthy so I have no intention on making usable knives out of them but I have been hammering blade shaped objects out of them to try and regain hammer control. I'm probably not even gong to sharpen the "blades" unless I just want to try my hand at shaping bevels, setting plunges, etc. So far the results are promising with steady improvement with each "blade"

My question is, if and when I get ready to buy good steel to actually produce something useable, what steels could be recommended that would work close enough to the same as what I'm using so as to not cause problems while I'm refining what skills I'm able to retain? In other words, I want to ease into this and let what muscles I have left get used to one thing at a time before trying something else that works differently

Link to comment
Share on other sites

1 hour ago, J Logan said:

close enough to the same as what I'm using

Old springs were 5160 so maybe start there.

"The way we win matters" (Ender Wiggins) Orson Scott Card

 

Nos qui libertate donati nescimus quid constat

Link to comment
Share on other sites

6 hours ago, Charles dP said:

Old springs were 5160 so maybe start there.

 

This.  5160 is good for many things.  There are easier steels to forge, like 1075, 1084, and W1, but 5160 is tougher in the end product. 

Link to comment
Share on other sites

Just stay away from those 3/8" thick, 3" wide truck leaf springs.  Those are a challenge for hand forging with two good arms, much less with one that is compromised.  I'm with Alan and would recommend one of the simpler series (10XX) if you are buying new steel.  Probably pays to think ahead to what you will be capable of heat treating.  

  • Like 1
Link to comment
Share on other sites

I make non knife things out of rebar, throwing knives, fire place and BBQ tools, hooks and tongs and things.  It's pretty easy to get, has an interesting texture built in, and comes in several sizes.  You sometimes have issues with the composition, I have had pieces break when quenched because there is a nodule of high carbon stuff in the mix.  As for known steel, what other people said, simple carbon steels, (10XX, 5160, W1/W2) are what I would use.  One that people miss is 15n20.  The New Jersey Steel Baron has it in thicker section.  It's like forging 1075 and the 2% nickel gives you a bit of corrosion resistance.

 

Go easy on the shoulder.  I had a rotator cuff repair, and while I'm pretty much back, it's good to remind yourself that it's never going to be 100%.

 

Geoff

  • Like 1

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

Link to comment
Share on other sites

I have an idea that I may help; I started using rail spikes to test new knife designs and processes to learn what parts of complex designs I should do first.  Itnis just an idea for you if you have them available to you. Moves easier that knife steel; won't stress your ability to heal, and could practice new creations in the process.  

 

I have resisted doing it for some time; I'm glad I started.

Link to comment
Share on other sites

Thanks for the replies. I'm as fully healed as I'm ever going to get. I just hope I don't do more damage trying things I shouldn't be trying lol. I'd like to be able to make knives, tools, whatever comes to mind eventually but right now I'm just hammering out knife shaped objects. I'm not sharpening them or anything like that, just working on hammer control. I don't mind wasting free steel, I just want to wait to buy good steel till I can satisfy myself that I can keep doing this. 

Link to comment
Share on other sites

On 3/30/2023 at 5:22 PM, Dan Hertzson said:

Just stay away from those 3/8" thick, 3" wide truck leaf springs.  Those are a challenge for hand forging with two good arms, much less with one that is compromised.  I'm with Alan and would recommend one of the simpler series (10XX) if you are buying new steel.  Probably pays to think ahead to what you will be capable of heat treating.  

Hi Dan,

I'd had a lot of success with coil springs and was planning to buy scrap leaf springs to try with these - I'd assumed that they'd all be a similar alloy but hadn't researched it. Should I be more cautious about selecting leaf springs?

Will

Link to comment
Share on other sites

If there is a spring shop in your town, see if you can buy their cutoffs.  Used springs often have micro cracks from use.  Those will get worse as you forge them and create lots of failures.  Generally leaf springs are 5160, but there are other alloys, so the heat treat will always be a mystery.  New steel is best, you know what you are getting and you know (or can learn) what the best HT is.  A stick of 1080 .250x1.25x48" is about $40 from the New Jersey Steel Baron.

 

g

 

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

Link to comment
Share on other sites

Will, since you're in Europe the alloys will be a bit different. 5160 is used, but so is 9260 (which I prefer!), EN43, and a few other alloys.  They all heat treat roughly the same, but it is nice to know what you've got so you can really dial it in.

Link to comment
Share on other sites

I agree with Geoff that you should attempt to go with relatively unused springs for blade forging when possible.  Steel over here is relatively cheap (though shipping to Scotland/Norway/Switzerland might be prohibitive:rolleyes:), and cutoffs are sometimes available from automotive spring replacement shops.  At times these can be found with little or no wear as they are being replaced by folks doing modifications to their stock ride.  I don't know what is available over there, but suspect there are sources for usable new steel. 

 

I've always treated leaf spring projects as if they were 5160.  Has worked for me.

Link to comment
Share on other sites

2 hours ago, Geoff Keyes said:

If there is a spring shop in your town, see if you can buy their cutoffs.  Used springs often have micro cracks from use.  Those will get worse as you forge them and create lots of failures.


Thank you very much - that's an extremely important point that I hadn't realized - those tiny microscopic cracks could open out during forging and cause havoc. (They're the sort of microscopic cracks that aircraft mechanics try to detect before they cause failure?)

Am I right in guessing that heating to forge welding temperatures then flux then hammering like hell might effectively weld the cracks shut but that success would not be guaranteed and that the cost of fuel and flux and time relative to the cost of new steel would make it a complete waste of resources?

I hadn't realized that there were spring shops - I don't know of any around here but I'll ask some mechanic friends if they know of any - one mechanic friend mentioned that old leaf springs were difficult to get because they failed much less frequently than coil springs and an HGV mechanic friend said that modern HGVs used pneumatic suspension not springs.

I'm working in the trees on the Northern flank of the Alps at the moment and had a hunt on Google and found some spring manufacturers - they don't seem like specialist automotive spring shops but maybe they'd produce scrap spring steel:

https://www.baumann-springs.com/de/

https://www.federtechnik.ch/

https://www.eglifedern.ch/

https://www.feder-matic.ch/

https://www.kubo.ch/en/Home/index.php

https://ressort.ch/en/
 

3 hours ago, Geoff Keyes said:

Generally leaf springs are 5160, but there are other alloys, so the heat treat will always be a mystery.  New steel is best, you know what you are getting and you know (or can learn) what the best HT is. A stick of 1080 .250x1.25x48" is about $40 from the New Jersey Steel Baron.

 

Thanks - it would be a big help to know the steel specification so that I can look up the recommended heat treatment instead of trying to guess it.

One problem I've run into here is that a lot of metal is only available in 4 meter lengths - so the logistics costs become vastly, vastly more than the metal itself. I need to try to track down more businesses that break those 4 meter lengths down into more practical lengths at our scale - I have been able to find one or two but I need to find more.

It's hard to explain to someone from the USA how dysfunctional Europe is - the situation would be like every state in the USA having its own individual postal system and any attempt to post something from one state to another turning into an exercise in international postage with vastly increased costs, weight limits, size limits and delays.

Link to comment
Share on other sites

3 hours ago, Alan Longmire said:

Will, since you're in Europe the alloys will be a bit different. 5160 is used, but so is 9260 (which I prefer!), EN43, and a few other alloys.  They all heat treat roughly the same, but it is nice to know what you've got so you can really dial it in.


Thanks - that's very helpful to know what alloys I'm dealing with - up until now I'd just been guessing.

Link to comment
Share on other sites

3 hours ago, Dan Hertzson said:

I agree with Geoff that you should attempt to go with relatively unused springs for blade forging when possible.  Steel over here is relatively cheap (though shipping to Scotland/Norway/Switzerland might be prohibitive:rolleyes:), and cutoffs are sometimes available from automotive spring replacement shops.  At times these can be found with little or no wear as they are being replaced by folks doing modifications to their stock ride.  I don't know what is available over there, but suspect there are sources for usable new steel. 

 

I've always treated leaf spring projects as if they were 5160.  Has worked for me.


Thanks - the warning from you and Geoff has been very valuable - I could have ended up unwittingly spending a lot of time trying to chase problems caused by microfractures in used springs.

I'll do some more hunting to see if I can find any automotive spring shops over here - the level of regulation on vehicles is vastly higher than in the USA so it may be that replacement or modification of springs with anything other than an exact copy of the original springs is forbidden and automotive spring shops have been regulated out of existence here - guessing that there must be some making leaf springs though to make replacement springs for classic cars and commercial vehicles or that a spring manufacturer like the ones above make them.

Link to comment
Share on other sites

I've go the reverse problem.  I really like 9260 but the only source for it here in the US stopped carrying it.  I found in the UK that the equivalent alloy is EN45 and I never found a supplier who would ship to the US.  I'll need to get my forge set back up, I was cleaned  out by a bugler, and I think I'll try 8760.

 

Doug

  • Sad 2

HELP...I'm a twenty year old trapped in the body of an old man!!!

Link to comment
Share on other sites

On 4/5/2023 at 8:09 PM, Doug Lester said:

cleaned  out by a bugler


Didn’t you hear him coming? :P

  • Haha 1

"The way we win matters" (Ender Wiggins) Orson Scott Card

 

Nos qui libertate donati nescimus quid constat

Link to comment
Share on other sites

On 4/5/2023 at 9:09 PM, Doug Lester said:

I've go the reverse problem.  I really like 9260 but the only source for it here in the US stopped carrying it.  I found in the UK that the equivalent alloy is EN45 and I never found a supplier who would ship to the US.  I'll need to get my forge set back up, I was cleaned  out by a bugler, and I think I'll try 8760.

 

Doug


Maybe I could try to get some over here and post it over to you? I'm in Switzerland at the moment. Trying to get suppliers to post things across the Atlantic sometimes works but can sometimes be a real pain...

Link to comment
Share on other sites

Thanks for the offer but I think that I'm going to go with 8670 which is considered an up graded 5260.  I hope that you are enjoying the spring in Switzerland.

 

Doug

HELP...I'm a twenty year old trapped in the body of an old man!!!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...