Old Leaf Spring from the creek testing scrap steel?

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Old Leaf Spring from the creek testing scrap steel?

Registered User
Joined: 05 Sep 2013, 19:46

29 Sep 2013, 17:31 #1

Recently the county highway department replaced an ancient concrete bridge with a new box culvert on the road on the east side of my farm.  In the process they regraded the shoulder for approximately 20-30 yards in both directions and made a wonderful sloped, grassy shoulder where there had previously been a sharp drop-off full of tall weeds, brambles and small trees.  It has become something of an attractive nuisance for trespassers.  Last week I noticed my cows staring in that direction, I walked over to get a look and the local petty thief was fooling around in the creek-bed.  By the time I got over to the area he had casually sauntered off, but I found that he'd been trying to dig some metal out of the creek.  I realized it was an old leaf spring, very well buried in the gravel. 

With a few tools I managed to dig it out, half because I wanted the steel and half to discourage the idea that we are a place worth stealing from.

It appears to be a very old spring, deeply rust encrusted like something out of a sunken ship, but underneath the rust, each leaf is still about 3/16ths thick, 3 inches wide.  At the rate I ever make things, this could easily be enough HC steel to see me out.  I cut off a chunk, heated it up past magnetic and quenched it in water.  It shattered quite satisfyingly when I smacked it with the hammer, so I know it will harden. 

I've read a lot on various places on the internet pro and con using "mystery steel".  I find myself coming down in favor of recycling stuff like this since I'm only doing it for fun and personal satisfaction. 

How difficult/expensive is it to have a piece of this steel analyzed for carbon/alloying?  My hope is that this is nice old fashioned spring steel in the eutectoid range perfectly forgiving of my cob-job blacksmith set-up and heat-treating abilities.  It is pretty hard to say how old the spring is, it seems to have been torn or cut off a vehicle  as the shackles and lots of torn chassis are attached on both ends, and there's a mix of hex and square nuts on the fasteners.


Registered User
Joined: 21 Oct 2006, 12:22

29 Sep 2013, 18:59 #2

If you are wanting to just hammer a blade out for you to get the hang of it a great piece to learn on, i think it be a perfect piece to have fun. Can not tell you how much or where to send it off to have it tested.

Registered User
Joined: 01 Feb 2013, 08:54

30 Sep 2013, 06:44 #3

As you are doing it for "fun and personal satisfaction", I don't see why you'd go to the expense and trouble to get it analyzed. Make something small out of it and see what happens.
Trees? They are all around me. I'd go mad without them.

Registered User
Joined: 16 Aug 2005, 08:06

30 Sep 2013, 18:49 #4

As this is kind of bread and butter metallurgical analysis, look at spending about $75. You could have it done for less if you have more samples, as many labs charge a minimum fee of 75 bucks. I'd say you could get it done for $20 dollars a chemistry if you can meet the minimum.

The other option, go get a university to do it for you. I'm not sure where you are, but there are quite a few universities that might help you out for a $10 lab fee, ect. For sample prep most require a flat ground surface that is clean of defects and about 0.75" square.

If all else fails, see if there is a steel foundry around you that could give you a hand.


Registered User
Joined: 26 Nov 2010, 02:47

03 Aug 2014, 05:57 #5

Why do all that? Spark test it on some sort of grinder, fuzzy means higher carbon. Long reddish sparks mean low carbon. If its normal truck spring, heat to non-magnetic; quench in oil, bake for 1 hour or more three separate times.