Work-hardening a sickle question

[SubterraneanFireForge]

Hi I’m not sure if topic should be in cold working or quenching and tempering so if this is in the wrong place please say so. 

I’m forging a sickle out of rebar this particular piece seems to have some carbon if I make a piece thin, quenched it in cold salty water and give it a bonk it will snap.

im thinking about work-hardening it

my question is would u work harden and quenched and sneak a piece, the same proses as with carbon high carbon steel? minus the normalization?

Or world u just forge it into a black heat and call it done?

Any general advice about sickles is also welcome!

Thanks!

[George N. M.]

OK, a couple things:  First, rebar is probably not the optimum steel to use for this because it varies in compostion pretty fast along the length of the bar.  It may be fairly high carbon at one point and a few inches away it is very different.  Frankly, given the amount of work and time you are going to put into this you are risking losing a lot of effort because the sickle may fail at an unexpected spot during fabrication or in use.  You may have a nice hard edge at one spot and it will bend like a noodle a few inches away.  I think you would be better advised to use something of more consistent content like a spring if you are using scrap steel.  Experiment with a sample (a "coupon") to see what quenching medium and tempering process works best.  You are more likely to come out with a good, usable tool.

Second, a sickle is nothing more or less than a specialized knife for cutting grain stalks.  Grain stems are pretty dulling to a blade because of the silica spicules in the stem.  So, I'd think that you would need a fairly hard edge so that you don't have to resharpen as often.  The blade is fairly long and thin.  So, I think you'd need it to be somewhat springy even though it may not get much in the way lateral forces in use.  I'd try for a differential temper with the edge being dark yellow or bronze and the back of the blade a blue.

I don't think work hardening is going to be much of an issue one way or another.  Yes, you could get some work hardening on the edge by hammering but IMO that would be of minimal effect compared to proper hardening and tempering.

And, yes, if you do have something with a resaonable amount of carbon, harden it, and then "bonk" it you will likely snap it off.  That is why you temper hardened steel, so that it is more bonk proof.

If you don't heat treat it at all you can sharpen it but it will dull quickly in use. Basically, you have made a wall hanger, an object that looks like a sickle but is not very good at doing what a sickle is supposed to do. Yes, prior to easy availibility of steel scickles were often made of wrought iron but I suspect that in use the scickle wielder spent almost as much time resharpening as cutting.

Finally, it is kind of tough to forge a curved blade with the edge on the inside because as you thin the edge the metal wants to curve away from the edge because while the metal is being made thinner the excess has to go somewhere which is spreading out.  Yes, it can be done but it takes good hammer control and a feel for how to counteract the tendency to curve away from the edge.  You may need to start with the thicker piece of metal than you would for a straight blade because in controlling the inside curve you may need more metal to avoid over thinning the back of the blade.  I suggest forging a practice one in mild steel or a piece of rebar and then, once you feel comfortable with the technique, make your final version in good, high carbon steel and then do your heat treating.  And, remember, if something is too thick you can always grind or file the excess metal away.  There is an old expression of "If a good blade you would win, forge thick and grind thin."

"By hammer and hand all arts do stand."

[SubterraneanFireForge]

Thanks for the information Gorge. I’m always surprised at how fast people respond on this forum. 

Having a lo carbon practice piece and a high carbon take 2 sounds like a good idea.

i recently acquired a car springs that I’m assuming would be good for a second shot. 
 

the yellow blade/ blue spine temper is a good point I’ll definitely try to temper it like that. 
 Thanks again!

[George N. M.]

Old car springs, either leaf or coil, are a good source of fairly high carbon steel but they have two possible drawbacks.  One, they may have thousands of little microfractures from long use of many, many cycles of being compressed and relaxed.  These can result in failure points when forged into a blade.  The newer the spring the better.  A good source are places that do custom suspensions where they take off and discard the brand new factory springs and install some sort of custom kit, e.g. lifts.  Second, some newer springs are odd alloys which are harder to work in a home shop.  Always, experiment with "coupons" to see how a particular spring will work, harden, and temper.  Once you have hardened it you can snap it in two and look at the crystal structure on the line of the break.  The smaller crystals the better.

Do you have some particular reason for wanting to make a sickle?  Maybe hanging it on a wall crossed with a hammer to symbolize agriculture and industry? ;-)

"By hammer and hand all arts do stand."

[Frosty]

George has this really well handled so I only have a couple little things to add. Do not fall into the trap of thinking that because leaf spring is already sort of blade shape it's THE stuff to use. If you're making stock removal blades then yes, it's the better choice. However if you are forging a blade use coil for two main reasons. First the shape doesn't lock you into one thing, round stock is round stock. Yes? The other and less obvious is the higher chrome content of leaf, it's increased to increase the steel's abrasion resistance, a stack of leaf springs does a LOT of rubbing when it works. The chrome can make interesting teat treatment but worse chrome oxide is VERY difficult to forge weld without very aggressive fluxes which ktend to give off toxic fumes in use.

My preference for differential tempering is a torch, heat the spine and watch the temper colors run and stop it when the edge is right. The steel is already hardened and you do NOT bring the blade anywhere near critical temperature so you can stop the temper with water, a wet rag is what I used when I made a long blade.

I've seen good results by tempering by sliding the spine of the blade on a piece of red hot steel and stopping the temper when it's right. The faster you slide it the slower it will absorb heat, and the tip WILL temper faster than the center or hilt end so watch it closely.

I much prefer a differential temper, the process is more controllable for an old blacksmith who doesn't make blades. I've made a couple just because but it's not my thing.

But having grown up in Dad's shop I absorbed a lot of heat treatment lore, about 75% of what he did required heat treatment, some ASAP, some did better with a rest period between spinning and heat treating. What you ask? Sorry that was all in Dad's head and it's a perishable knowledge as are your parents. <sigh>

Frosty The Lucky.

[Nobody Special]

Regarding sickles and scythes, at least traditionally they were sharpened constantly through the use of whetstones and peening the blade's edge way thinner than feels comfortable on a small stake anvil. It's a righteous pain to do until you get used to it, but in the right hands (i.e. not mine) they cut insanely fast. This has changed somewhat in America, where the tradition is to have a thicker spine and sometimes the beveled part of the blade.

The videos of cutting grass with a European style scythe are hypnotic and almost feel fake, especially if you're watching one where someone almost keeps up with a modern farm machine.

[George N. M.]

Back in the late '60s and early '70s I had a friend who had an elderly great aunt who lived in the back of beyond, West Virginia and cut her tall grass with a scythe.  She complained that you couldn't get goof, American made, scythe blades any more and she had to buy imported Austrian (IIRC) made blades.

There is a great hardware store (Arp Hardware) in Boulder, CO which still stocks scythes along with all the other shovels, rakes, etc..  If you are ever in Colorado Arp Hardware is worth a trip to Boulder.  There is very little that a person needs in life other than food and clothing that they don't stock.

GNM

[JHCC]

Here are two good videos about scythe forging, the first from Torbjörn Åhman:

And the second from the Northmen channel:

 

[SubterraneanFireForge]

Thanks for all the information everyone!

im making a sickle because I volunteer at a garden and pull mugwort by the hour, so I was thinking a sickle could come In handy and be a fun project that I can forge and test. 
 

The springs I got are pretty new but I’m just curious. would normalizing a piece of steel or heating it to forge welding temperature before working it fix any micro fractures. 
 

[George N. M.]

I have heard that heating to forge welding temps will not "heal" micro fractures in a spring but I do not have any first hand experience.  I yield to those with more specific knowledge.

GNM

[JHCC]

The problem is that mugwort easily regrows from its roots, so cutting it back doesn't get rid of it. Instead of forging a sickle, you need to think about  making some kind of weeding claw that will help you get the entire root system out of the ground, as it can easily regrow from a single rhizome. 

[George N. M.]

Here is a link to a report of a recent Bronze Age find in Poland which includes bronze sickle blades.  I imagine that using a bronze sickle would involve a LOT of sharpening but it must have been worth it compared to the alternative.  I recall seeing Neolithic sickles with flint blades set along a curved wooden handle.

https://www.thehistoryblog.com/archives/69628#respond

[Frosty]

Thank you for those links and rabbit holes John. There is lots of good watching, I learned one important thing about sythes, I have no, ZERO interest in a "short" sythe, did you see how far the smith was bending over to cut grass? At least a little more handle for me please!

Mugwort needs to be pulled when it's young, give it time to mature and you need to poison it or start digging.

This is a good article. https://ipm.cahnr.uconn.edu/invasive_plants_common_mugwort/

I remembered to copy my sig line this time! Good luck, the stuff is a bear to eradicate. 

Frosty The Lucky.

[SubterraneanFireForge]

I just finished temping and sharpening the sickle.

it was all forged to finish apart from the last little bit of sharpening.

That’s a good point Jhcc I hadn’t thought of that we normally turn over the dirt and sift out the bits of roots and little weeds so it might not matter.

a weeding claw might be a fun next project!

Gorge I haven’t seen any tangs so small to u know how they would have to mount to a handle???

after watching that video I might have to try making a scythe next. 

[Frosty]

That's more of a short scythe than a sickle. A sickle has a more curved blade, think sickle moon. Yes?

A scythe has a "snath" with usually screws, bolts or wires on to a flat tang.

Instead of just asking the world through Iforge a simple search for sickle handle will provide pictures, descriptions and useful info if you stay off YOUTUBE.

I just looked up what I said above, took maybe 3-4 minutes

Frosty The Lucky.

[SubterraneanFireForge]

Thanks Frosty,
I’ve found plenty of pictures online of flat, mostly Japanese sickles. 
some with spike tangs. 
From what I gather the curved sickles are more for gathering while the flatter sickles are more for just cutting stuff down like when your weeding. 

I did welcome any general advice about sickles, but my original question was about combining work hardening and heat treating, which I couldn’t find information on in other places. 

[JHCC]

21 hours ago, Frosty said:

think sickle moon

"I shed many tears before the thin moon rose up, frail and faint as a sickle of straw."

-- Dorothy L. Sayers, The Nine Tailors

[Irondragon Forge ClayWorks]

On 3/7/2024 at 2:35 PM, SubterraneanFireForge said:

a weeding claw might be a fun next project!

I have made some from old fifty cent yard sale claw hammers for my gardening friends and they seem to really like them.

I can't control the wind, all I can do is adjust my sail’s.
Semper Paratus

 

[Mike BR]

I think I’d hold out for a motor sickle. 

[LarryFahnoe]

"... I don't want a pickle Just want to ride on my motorsickle ..."

Thanks Arlo!

[SubterraneanFireForge]

it looks so funny it’s like someone dropped a anvil on a clay hammer. ill be looking out for stray claw hammers that look like they want to try something new.

“…and I don’t want tickle id rather ride motorsickle…”