Leaf springs are typically 5160.
Old springs often have dozens of micro-fractures that you can't see
with the naked eye.
The question I have is why are you welding it?
Is it with the intention of putting it back on a car?
In general that is a very bad idea.
If the spring is trapped inside the bundle of springs you might get
away with it, but if it is the spring that goes to the spring
mount.......again, bad idea.
To effectively weld a spring you would have to v-groove the break from
both sides, preheat it to at least 600 degF, weld with a high strength
rod such as 10018, and then slow cool under a pile of sand,
vermiculite, ash or powdered lime.
After welding, clean it up and once again heat it to about 600degF,
then air cool.
Maybe, just maybe that would work, but I would just raid a junkyard for
Thanks Ernie for the assistance. My plan is to use it in a post type 'power
hammer' where the weld will be trapped and there would be full length
springs on each side of it.
I have used wood ash before to treat a trailer hitch ball mount bracket and
it seemed to work fine. I forged it to cherry red and buried it in the
ashes overnight. It was still quite warm 20 hours later. So far it has
held up good. I didn't do the second heat but I have seen videos where that
is used almost all the time. Especially for annealing where they leave it
in the oven overnight to cool. Makes the piece soft and ductile so it can
I have used 10018 on 3/4" thick 50 hp electric motor mounts of vibratory
shakers and it turned out to be too brittle. I was supprised when the 7018
held up quite well.
Somewhere I read that auto leaf springs are like tool steel, 1095. The ones
I have don't spark with a white spark though. Can't touch them with a drill
bit. And I would hate to waste a bandsaw blade on one that a drill bit
won't touch. . . . .again thanks. . .chas
That is because you didn't preheat, and slow cool.
7018 does yield a very tough strong weld, but it is not as strong as
1095 is only used for small springs.
Mid-sized springs are often 1080, but for large springs you want less
carbon and more alloying elements.
5160 is a great knife steel for super tough working knives, and is the
most popular sword steel in the US.
Ernie, what is the most common source of 'scrap' 5160?
Is it found in any particular brand name car/truck leaf spring (coil maybe?)
? I have some coils I have never used.
What is its spark characteristic when hit with a sidegrinder?
. . .thanks for all . . chas
5160 is used for all leaf springs and most large coil springs.
For thicker pieces you need to go to truck springs.
For thinner stock, small import cars are good.
Any junk yard sells leaf springs.
Coil springs are useful for forging smaller knives.
First you have to heat them with a torch to straighten sections.
Again you don't want really old springs. They tend to have more
Only if you are making damascus, and are going to stack and compress
That should render the micro-fractures moot, but otherwise they can
stay in the steel, and will likely propagate during heat treat.
For this reason smiths, making their living with knives, buy new 5160
bar stock rather than take a risk with an old spring.
Hi Ernie, all
Given knowledge apparent...
If I wanted a sailor's knife, for cutting / trimming rope, any idea
where to look? Want something small and light so can carry all the
Carbon steel blade would be fine as can lightly oil it.
Spyderco sells a lot of knives to fishermen.
The Endura line doesn't cost much, so if you lose it, it isn't a big
Spyderco serrated edges work pretty well on heavy rope.
Spyderco and Benchmade both make knives for marine use made from a new
steel called N680.
N680 is incredibly rust resistant even in salt water, and it holds a
very nice edge.
It is called a Nitrogen steel, and it doesn't refer to the heat treat.
There is actually nitrogen in the steel.
Bohler Udeholm came out with N680 a few years ago and it is a big hit
in the diving, fishing and of-shore oil industry.
The classic sheeps-foot blade and marlin-spike riggers knives are still
made by a few companies.
I am not sure on exact brands, but you should be able to google it.
The Navy used to buy crates of them from Camilus.
Most fisherman don't want to spend too much on a knife since they often
Blade steels are all pretty good nowadays, but you do get what you pay
Thanks guys. Yes, a mate offered me his Navy knife from decades ago
but I couldn't take that knowing each knife will only last a few weeks
Opinel is well-known here in UK but has curved blade. Apart from
anything else, a short straight-edge blade simply does not look that
I was thinking of a source of knives, buy a few at a time, use 'em
hard and keep getting replacements from the ones who saved your hide
time after time.
Marlinspike is useful but not useful enough to me to carry all the
time - and a marlinspike looks kind of scary to the unitiated.
Thanks for all hints.
[This "scary" and "offensive-looking"... The trouble we have had
working here in London, UK as steel-erectors (N.Am. - "ironworkers").
Imagine the scene when you are entering the "Tube" (subway-train)
station and a group of police-officers who have grown up in "the
service economy" stop you wanting to know what your tool-chest is.
Then their stunned eyes come into sight of tools like your podgers
(N.Am. - "spud-wrench"). People have had to walk back to site and
leave their toolboxes at the site office and work out how to get it
back to the yard later. I used to wrap rope around my toolbox bound
tight with the largest most complicated-looking knots I could devise
in the hope of causing various officials to not want to spend the
unknown time of getting involved. It also looked the part, spoke of
something big and real out beyond their familiarity, etc.]
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