if you grind out the shape of a sword in a leafspring, is the heat treating anihilated?

Probability are than, yes, you'll just mess the heat-treatment. However, I think it's possible to do it if you take care of cooling the blade with water every few minutes, to be sure it doesn't get hot.

If I remember correctly, someone on the forum did something like that (reshaping a blade) for a basket-hilt customization project.

how do you get the bend out of the spring? you can't forge it cold and if you warm it the heat - treatment is destroyed anyway - except it is air-hardening steel (as i wrote in the training sword topic).

Looks like I read to fast...

If you want to forge a sword from a spring, you need a forge, good dose of patience and someone competent to teach you.

What about getting a look to the famous book by Jim Hrisoulas, "The Complete Bladesmith: Forging Your Way to Perfection" ?

Has for grinding only, not sure if its possible...

Leaf springs in the U.S. are usually 5160, which is an oil hardening steel. To straighten the bend you would probably want to heat the entire spring to at least 400 degrees F. but probably not more than 550- this temp range is generally within the tempering specs for spring steel. The trick here is to get the straigtening done before the blade loses too much heat. With a leaf spring this would probably take numerous heats.
Grinding on steel that is already heat treated is done as a matter of course in blade-making, the difference in what you are talking about is that you wiull have a great deal more material to remove than if you rough out the blank before heat treating. All in all it is far from an ideal method for making a sword.

Yeah but just take the toni R. spatha, it is made out from a leaf spring and it looks good to me.

I would grind out the blade without gloves or very thin ones so that as soon as the blade becomes too hot to hold it should be cooled with water. I can see some danger when the blade gets close to being sharp that holding the blade with naked hand could become dangerous.

In any case using short and light passes on the grinding wheel as pressure and too much work without stopping to cool things down can cause localized overheating.

With polished in the white steel overheating might be visible as the steel would start to turn colours as it overheats and thin sections will overheat the fastest.

So avoiding ruining the temper is possible but the pace of the work has to be adapted compared to a piece that will be heat treated later.

My knowledge of this is mostly theoretical but I have made a few knives or short swords a long time ago that where from heat treated steel. In fact one error I made early on was grinding out a blade from a large file. I certainly didn't ruin the heat treat, in fact I should have heated it to around 450 or 500 degrees for a few hours and let it cool slowly because it turned out that the dagger blade I had made from the file was still glass hard and broke in two when I did a test hit on a large log ( piece of firewood ).

I certainly wasn't trying to be discouraging, just trying to give some insight. Bending a heat-treated piece of steel can be a hit or miss operation-there is always the possibility of causing stress fractures or other faults in the steel, which may or may not be apparent. Heating to the tempering range will prevent this to some extent but temperature control is important.

I thought of something yesterday and i want the opinion of a professional sword maker.

you know that if you want to do an armor piece you can take two things to hammer on the anvil and a stump.
so my question is can we hammer a red hot leaf spring on a wood stump and have a good result?

if you make it too hot, the heat treatment will be lost, but furthermore I think that most wood stumps have too narrow a curve to eventually make the sword right

i forgot to say that i would (if it's a good thing) use the stump for straightening the blade after i making the blade with a leaf spring (if you did not understand) :D .

I just bought a piece of 5160 from a local supplier. The steel is already tempered and I am going to cut out the sword with an oxy-actelylene torch and grind from there. Years ago, I used this technique to make knives and was very successful. Do what Jean says and wear no gloves and cool frequently with water. I dipped rags into a bucket and slopped the water on while the blade was still clamped in a vise for the coarse shaping grind ( hand disk grinder). I quenched it frequently in a bucket during the final grinding (belt sander).

The pretempered bar steel that I bought is .213" X 2" X 22 ft. The piece cost $43.00. Using straight pretempered steel will get you out of trying to straighten the car spring. My personal experience with car springs is that they have to be heated to cherry red, hammered flat and the re-heated and annealed in order to use them. Otherwise the spring will re-bend when you start working it.

One more thing -if you cut your shape with a torch- cut it oversize and grind to final shape. The area where you make the cut will be affected by the heat - grind away anything that turns blue.

Good luck.

I saw something in my town, it was a thing that cuts metal by water pressure. it seems that it cuts it really fast and it doesn't burn the metal. did you know about these things?

Jean wrote:

Or do all the profiling with the grinder but expect it to take a long time and many many grinding belts.

By the way the best machines for this type of work are the ones using abrasive belts, the machines using round stone-like abrasive wheels may vibrate too much and the diameter becomes smaller as the wheel wears out.

For rough work one can use a hand held angle grinder with the steel held in a vice moving the grinder instead of moving the steel against a bench grinder: A lot of improvised methods can work but each has it's pitfalls.

Oh, using a dremel and a cutting wheel one could cut a rough profile instead of using the acetylene torch and with less risk of overheating the blade.

If you can find a place to heat treat your finished blade after you have it 95% ground to shape you could avoid all those issues of ruining the temper and the steel will be much faster to grind soft.


Jean,
I used all the techniques you mention making knives from pre-tempered planer steels - sawmill size bandsaw blades (1/8" thick and very springy) and old files.

I used a bench grinder with a stone wheel only for trimming the jagged edges of the torch cut. Final shaping and the bevels were done on table mounted belt sander using progessively finer belts.

The dremel works well, but I used a larger air driven die grinder. I was fortunate to work in a shop with lot of power tools.

Eventually I graduated to buying annealed tool steels and cutting out the knives on a band saw. I ground and filed the bevels, ricasso, choils handle shapes etc. This made for a much nicer job. I made knives up to 18" long.

Heat treating was done with an oxy-acetylene torch with a rosebud tip and an improvised forge made from pipe lined with asbestos sheeting ( that will tell you how long ago this was). Works fine for knives, but I doubt that you could heat a 36" blade evenly enough for a good heat treat.

Hello all!

I try to make a sword from leafspring. Overheating can be avoided, but that's not my primary concern. Leaf springs are already heat-treated, ideal for absorbing shocks, but I dont't think they will have good edge retention. Is there a method for quenching just a few millimeters of the edge, leaving the rest unmodified (like hacksaw blades)?

Arpad