Rail road spikes (HC)

G

Godless907

Joined
Jun 5, 2010
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I just recently took up Blade smithing. Made a few junk knives out of some cheep low carbon steel for practice. But about a week ago I was lucky enough to stumble on a pile of High Carbon RR spikes. I just finished my first twisted handle blank getting ready to file it down (no grinder yet). But I have no idea how go about heat treating the HC spikes. So if anyone has any experience with these I could use some pointers. I doubt the book I orderd will be here b4 I have to go back to work.

Thank you
 
If the spikes are actually high carbon (1+ % carbon), you can heat to non magnetic and quench in oil. You must then temper the blade by heating it to the proper temperature and air-cooling it. 400 degrees is a good temperature.
 
Thnx.. now my next question....heat till non magnetic?!?.




Good lord Ive been researching and testing and pounding.. filing... reading ... and everyday for the last 2 weeks I learn about 10 new things a day... Too late to turn back now im hooked :)
 
No idea what mine were, low carbon/high carbon but i had to use cold water to get it hard enough. They were very old with no markings

Richard
 
High carbon spikes have HC stamped on the top of them and are used mainly in turns in a track.... If there were no markings then most likely they were just normal spikes.. but they still have a decent amount of carbon
 
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Ok ive done some further research and Ive read that im looking for a temp of about 780 or cherry red.........OK so cherry red .. Oil quench.... then heat to about 400 (from what I gather from other post) maintain that for about an hour then air cool then I should be good to go?!?


This sound Viable?

oh and what kind of oil I need.... dose it matter reg old engine oil work?
 
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if you use old car oil it will flare up a bit as you quench so keep your hands clear and keep it away from anything that burns, heard a lot of people using veg oil or Canola even peanut oil, they will all smell a lot nicer than car oil, I use quenching now but have used car oil before.
Cherry red in a dark area, you can't see the colour in sunlight, temper in a oven but give it the file test first, if you can just file it with a sharp file it may not need tempering, if the file skates across the blade then temper it.

Richard
 
Use a magnet to test temp, nonmagntic, when the magnet no longer attracts to the steel. the temp you are looking for is much higher than 780 degrees "F" will be around 1450+ "F". ATF fluid will work, veggie oil, minerial oil, heat oil to around 120 degrees. Hope this helps, Dale
 
You need to sit down and take the time to read the stickies and tutorials available here and other places on line. The sticky on heat treatment of 1080 by Kevin should be a viable attempt for a HC RR spike.

Heat to non-magnetic and quench in oil is a short phrase for the simplest heat treatment procedure. What is actually means is to heat the steel to the temperature where a magnet will cease to stick to it, plus about 100F/40C. This would be about 1450F/780C. Then you quickly quench in a oil quenchant. The commercial quench oils would be best, but canola oil, peanut oil,and ATF will do for starting oils. A RR spike can be quenched in brine with little risk ( and will harden better). The brine quenchant is a 7-10% solution of rock salt and water. That is about 1 pound of salt for every 1.5 gallons of water.
Once the blade is quenched, keep the blade immersed in the oil/water, moving it up and down, or from spine toward edge, but not from side to side. Once the steel has cooled in the oil/water for a minute, check for warpage, and if all is well, clean the blade well with dish soap and water, then place in a 400F/200C kitchen oven for two hours.Remove the blade, cool to room temperature, and place back in the oven for two more hours. At this point the blade is hardened and tempered. Sand to the desired finish, attach the handle, sharpen and enjoy.

Now, what happened in all that was:
The spike is made of steel, which is mostly iron, plus a tad of carbon, and some alloy elements. The carbon % is about .30-.40% in a HC RR spike. (That would be called low carbon in blade steel, but is high compared to regular RR spikes). The carbon is tied to the iron in a structure that is relatively soft. This structure is called Pearlite. When the steel is heated to above 1350F/730C the structure changes to austenite.You heat it about 100F/40C higher to allow all the carbon to diffuse. When this cools back down it will change back from the austenite. If cooled slowly, it reverts to pearlite. If cooled rapidly, it converts to martensite, which is the structure we want for knife blades. Martensite is hard but brittle. The brittleness is removed to an acceptable degree by tempering the blade at around 400F/200C. This allows the structure to rearrange a bit to a tougher form. It is cooled and repeated to finish the process.
 
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i have been told to quench themin Super Quench- salt water with dawn soapadded to try to get them to harden. I have never found any evidence they were above .30 to.40 carbon.Not enough to really hold a good edge forany length of timebut they do look good. I have probably 50 lbs.of them just never tried more than one.
 
Yes, adding dish washing soap to the salt water quench tank helps break down the vapor jacket by lowering surface tension ( the vapor jacket has a surface). This will help drop the temperature faster, which in low carbon steels is crucial to getting it hardened fully ( as fully as it can, anyway). About an ounce per gallon is plenty.
 
Here’s some super quench recipes, from Rob Gunter and theforge, and some data on HC spikes…

5 pounds salt, 32oz blue Dawn dishwashing liquid, 8oz Shaklee Basic
I wetting agent, add water to make 5 gallons of solution.
Stir it up to get it moving before you quench. Don't quench anything
with more than 45- 50 points of carbon.
*************
You can also use Simple Green as a replacement for the Shaklee
product. You can get this at Wal-Mart.
**********
>5 gal water
>5lb Salt
>32oz Dawn (blue) dishwashing liquid
>8oz Shaklee Basic H (or other surfactant of appropriate quantity for 5 gal mix)
>Will harden mild steel to Rockwell 42-45 (in spite of common wisdom that
>says you can't harden mild steel).
That's an old formula.
Dawn is now a "concentrate". Use the 28oz bottle.
Jet-Dry "liquid rinse agent" can be substituted with terrific
results (and it's a lot easier to find) for the Shaklee product(s). Use
the UNSCENTED 7oz bottle.
The Jet-Dry (or whatever you use for a rinse agent) does something
chemically to the surface of the steel. It allows the salt in the mix to
start attacking it as soon as it hits the air - make sure you have a LOT of
clear water to rinse in ready at hand.
Quench a chunk of low-carbon scrap stock in it, and just set it
aside. You can *watch* the salt eat into it.
************
Jet Dry, Calgon, and other surfacants are wetting agents. They break
down the surface tension of water allowing it to make contact with a
meterial. We've all dipped a cold piece of metal in water and seen a
bubble-like "skin" form with dry metal under it. This is surface tension
trapping a layer of air, it makes a fair heat shield.
In a quench, steam will form a similar surface "skin" and prevent full
contact with the water, insulating the steel from a proper chill.
Wetting agents prevent the "skin" from forming.
Detergents do a somewhat similar job, they're emulsifiers allowing oils
and water to mix. This prevents any oily residues from the fire from
forming a "heat shield" surface layer.
The salt in the water raises the boiling point and causes a faster,
harder chill in the steel. In effect but not exactly, it raises the
specific heat of the water and draws the heat from the steel faster.
************
Railroad Spike Info:
From a section of High Carbon RR spike sent in for analysis to U.S. Steel, as
there had been several people inquire ( as well as satisfying my own curiosity ).
Here are the results:
Carbon - .296 %
Manganese - .68 %
Phosphorous - .016 %
Sulfur - .038 %
Silicon - .244 %
Copper - .287 %
Nickel - .09 %
Chrome - .13 %
Tin - .001 %
Aluminum - .005 %
Vanadium - .022 %
Cobalt - .008 %
High carbon spikes were made exclusively starting in or around 1974 to replace the
low carbon spikes currently out there, and were generally just iron and carbon
(with a couple trace elements thrown in for special areas).
From:
Steve Rabuck
Beloit, WI
(theforge)
For High-Carbon Steel Track Spikes:
Process: Steel shall be made by one or more of the following processes:
open-hearth, acid-bessemer, electric-furnace, basic-oxygen.
Chemical Composition:
Acid-Bessmer Other Process Carbon, min. percent 0.20- 0.30
Copper, when specified:
0.20%
Tensile Properties:
Tensile Strength, min. psi. ............................70,000
Yield Point, min. psi. ....................0.5 tensile strength
Elongation in 2 in., min percent.......................... 25
From:
Machinery's Handbook
Marking:
Manufacturer brand and the letters "HC" indicating high-carbon, and when copper is
specified the letters "CU" will be added.
 
RR HC spikes make a cute paper weight, or letter opener, but thats about it! Non-magetic is not enough heat to quench any steel at, or any that I know of. Non-magnetic is 1414° F. The minimum temp for quenching most common carbon blade steels, assuming you want a good result, is 1450°, with 1475° most often being better, and for some common carbon blade steels, 1500° to 1525°. Non-magnetic does form austenite, but not of the degree or quality to make good martensite with a good homogeneous condition of iron and carbon when you quench. Far too many are overly concerned with grain growth above non-magnetic. 1475° or even 1500° will not cause any appreciable growth if you have properly normalized the steel as you should have before heating for the quench process.
 
Just my opinion, but railroad spikes should only be used for Railroad spikes, or to be thrown at wild dogs trying to get into your trash cans. :p:D

Seriously, why waste time forging and grinding something that has zero chance to become a good blade? Good, known quality steel is cheap enough. Buy some known quality steel, would be my recommendation.
 
Rob Gunter used to do this demo- He'd take a bar of 1/2" sq. 1018, cut a piece off, forge it into a cold chisel, quech in super quench, sharpen it, then use that cold chisel to cut the rest of the parent bar into pieces... without damaging the edge. HC spikes make a cool novelty knife, of course they aren't a good edc, but you can get them to hold a bit of an edge.
 
Wow Thank you all for the info. Here in Alaska finding stock steel other than lowes junk is hard so im stuck with what I can find till I can find a good online supplier. I was lucky enough that my brother in law had a forge and anvil w/stand that I could borrow so I didnt have to drop a bunch of cash on somthing I may not like doing. Down at the tracks I found a pile of HC spikes so im stuck using them for the time being. But Ive made 1 junk steel(lowes) knife and done 3 blanks from the HC spikes and well... im hooked Ive already picked out my next forge.

Again.. Thank you all alot for the info

Eric
 
HC spike are 1020 to 1030, which is a low carbon steel. The HC only means they have a higher carbon content then unmarked spikes, which run 1006 - 1020. CU spike are 1020 and have copper added.

Forge them all you want, you will learn a lot for little cost.

From my experience, there is no need to temper them back, because of the low carbon content. But you can experiment, temper one then don't temper the next and see which blade cuts better.

Spike manufacturers adhire to A.R.E.A. specs (A.R.E.A. merged with A.R.E.M.A. in 1997). Here is their website: http://www.arema.org/
 
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