Turbo Dog

How do I harden old railroad spikes?

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Howdy all, just a small time WY cowboy looking for advise from yall.  New to this forum, found it trying to look up heat treating info.

A long time ago, needing a tap with none around to chase some threads a man showed me how to cut two grooves in a bolt, taper the leading edge, heat it red with a torch and cool it in motor oil.  It worked, but doing some reading on this site brings up more questions.

I have a small pile of old railroad spikes, might be from the 1800's.  Not sure which exact metal they are but I need/want to make them harder.  I am using them in a homemade harrow to bust up the washboard bumps in my gravel road.   They are about 3/4" square, maybe 8" long and have a bit of surface rust.

I can get some canola oil and all I have to heat them with is an oxy/acetolene rose bud torch.  Should I be heat treating them or should I peen them with a hammer?

 

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Well, it's probably not worth the effort. 

IF they are not wrought iron spikes and steel, you might Mildly get a little more hardness but not much to make a difference. I doubt case hardening is worth the effort for inteded use either. 

 

Any access to coil springs at a mechanical shop? 

If you can build a fire on the ground and find something to blow air under the coals, you pretty much have a forge. Way cheaper ways than O/A torches. Look up JABOD forge. Super cheap and effective. 

There is a spark test chart online to guesstimate steels, which may be useful to you. 

Ugh, just too much info here to reference.  

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Thanks, I can probably come up with some used coil springs, guessing that leaf springs would be equal.  True?

Of course a used cutting edge from a snow plow would be harder, but do I ruin the hardness on any of these when I  use a torch to cut them into pieces.

I'm easily wearing down the railroad spikes.

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Yeah, leaf springs are also harder and hardenable.

You do ruin any hardening/ heat treat in the HAZ when you torch them. 

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If you have access to construction scrap you may be able to get some grade 8 bolts in 3/4 inch.  I can tell you from personal experience that those are pretty tough customers.  I am able to get them at scrap prices at my steel supplier....you may get lucky.

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No one has suggested that you just get a good high carbon metal and make a rail road spike from that. Being a known metal, you will also know how to harden it and make a decently harden rail spike. (grin)

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Welcome aboard Turbo Dog, glad to have you. If you'll put your general location in the header you might be surprised how many of the gang live within visiting distance. 

I'm afraid RR spikes are at the high end of low carbon steel. They need to be tough, take millions of cycles of stretch relax forces without becoming brittle. You do NOT want RR spikes to work harden and snap. There is very little heat treating can do for a spike except relieve work hardening, normalize or anneal. 

It'd depend on what kind of snow plow cutting edge you were thinking of. If it's like we used on State Highway plow trucks it'd be okay but a serious bear to get shaped and heat treated. You don't have the equipment to heat treat it, we're talking ramping kiln type precision. 

Coil spring was what came to mind when you said you wanted to make a road harrow. Oh yeah, coil spring should work a treat, you don't really need sharp to break up the washboard, it helps but what works better is if they chatter in the frame. The expensive factory made units use carbide drill teeth they look like large square lathe cutters. 

I'll have to think about how I'd connect them to the grader frame. Angle iron flange up and forward with the teeth, scarifiers I suppose, extending downwards. I'm thinking the teeth are shorter than the angle iron is wide but I'm trying to picturing the one I looked at a couple years ago.

Heck if it's not too hard a road you can drag a piece of chain link fence and it'll smooth things up nicely. Heck I'd put chain link to help carry and smooth the material that's scraped off the high spots in the low spots.

Yeah, coil spring, Ideas to mount it are starting to perk. I'll get back when I think of something.

Heat treating coil spring is pretty easy, it's pretty forgiving of mistakes. Don't use motor oil, the smoke's too toxic, besides the petroleum smoke there are all the metal residues antifreeze and combustion products that blow by the rings. I bum a jug of used fryer oil from the deli section of the local Safeway when I need fresh . . . er. They change oil regularly and I ask ahead of time then I bring a clean plastic jug with a label and check back when they say the job'll be done. Some markets change on a scheduled basis and the folk buying the used oil aren't likely to miss a few gallons.

Or you can buy a 5 gl. just of new canola oil for not a whole lot. Just don't use motor oil, it's nasty stuff. Okay?

You can heat treat in a charcoal fire with just a little added air blast. Bring it to non-magnetic and quench in warmed oil. When you have a batch hardened wash them to get all the oil off and put them in an oven . . . DRATS I can't think of the temp. There's temper color charts linked here, I can't remember where. Anyway, for this you want to shoot for a dark straw verging on purple temper color it'll be hard enough but not so hard it'll be brittle.

Oh, good details are in the heat treating section of Iforgeiron. 

I'll do a little brainstorming on your project and should have some suggestions after a while. My memory isn't so good, it's all in there but the filing system is pretty scrambled. It's a TBI thing.

Frosty The Lucky.

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Well the older they are the lower in carbon content they most likely will be.  Higher carbon contents are associated with the modern spike driving machines and as mentioned top out at the mild/medium carbon steel border.  There is a method of hardening steel with some C but not a lot: look up "super quench"; but on an old mild steel spike ity might not do much---you can try it and see if it does any good on what you have though.

If you have access to a friend with a powerhammer you might be able to make spikes from car axles and heat treat them.

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just a twopence worth..

supersaturate brine...ICE cold...works ok...do an edge only quench and no need to draw if back....I do get a usable knife out of a RR spike but then again..I tend to be able to do a lot of stuff that most folks can't figure out how I manage it...  I make my RR spikes a bit different from most others that make them...they are very quick to do..I figure I have about 12 to 14 minutes in each one

JPH

DSC03865A.jpg

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I wouldn't think you'd need to draw it back in any case but I'm not a bladesmith guy. 12-14 minutes eh, get the press working? 

Yeah, you do stuff lots of folk think can't be done, not a surprise. 

Frosty The Lucky.

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RR spikes are 5/8" square.  they are about .29 points of carbon is high low carbon steel.  If you forge the blade, then quench it in Super Quench (5# rock salt, 24 oz blue Dawn dish soap (the concentrate) and a bottle of Jet Dry (dish washer spot remover) and fill to 5 gallons of water) you can get a hardness of about 53 RC.   Try bringing the spike to non-magnetic and quenching in water, then bring it up to non-magnetic and quenching in Super Quench and listen to the steel SCREEM!

Let me know if I can help you;.

Wayne

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Wayne, is it plus 5 gal. of water? Maybe it is not that critical.      Thanks - Jerry

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Thanks for all the info...the railroad spikes are very old from an abandoned railway, probably the early 1900's.  I'll check with some of the auto repair shops to see if they have any coil springs laying around.  Or I'll try that Super Quench method.  The spikes are able to rattle around in their mounts and the harrow has done a much better job on the very hard well compacted recycled asphalt road since I added two pistons out of a Cat 3608 for weight, but it is also eating the spikes up faster.

I found and bought some new bucket teeth, that are similar to this picture.  Would they be already hardened?

 

Bucket tooth.jpg

On 10/2/2018 at 7:12 PM, WayneCoeArtistBlacksmith said:

RR spikes are 5/8" square.  they are about .29 points of carbon is high low carbon steel.  If you forge the blade, then quench it in Super Quench (5# rock salt, 24 oz blue Dawn dish soap (the concentrate) and a bottle of Jet Dry (dish washer spot remover) and fill to 5 gallons of water) you can get a hardness of about 53 RC.   Try bringing the spike to non-magnetic and quenching in water, then bring it up to non-magnetic and quenching in Super Quench and listen to the steel SCREEM!

So do I fully submerge the spike each time and move it around in the liquid, or just drop it in?

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Guess I started this in the wrong section and they advised asking my question here.  I have some old early 1900's railroad spikes on a home made harrow that is being dragged on a very hard compacted road made of recycled asphalt.  They have suggested old coil springs would be better to use or to Super Quench what I have.  I also have some new bucket teeth and am wondering if they will do better.  I end up grinding off about a 1/2" off the spikes each grading session which drags the harrow about 2 miles.

https://www.iforgeiron.com/topic/60000-how-do-i-harden-railroad-spikes/

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Move them around (and probably won't do much with the earlier spikes.)

How do you harden mild steel?  You throw it away and replace it with an alloy that will harden.

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Old spikes were even lower in carbon than the HC spikes that were introduced when they got powered spike drivers and didn't drive them in by hand anymore. No they are not hardened to any effective standard---try filing them to check.

As they are low in carbon content the methods of hardening are pretty much limited to work hardening which is not really good against wear such as your use entails and cementation---soaking carbon in to make blister steel.  However that would take more time and energy cost than starting with a higher carbon source and forging spikes from it.

If you are going to drag them in asphalt you need to use what they use for wearing against asphalt---the wear plates from road graders or the carbide knobbies thy use in the machines that chew up the top layers of streets to reprocess it into fresh paving materials.   Bucket teeth should be a very wear resistant alloy too.

You might ask the road department if thy have any scrapped carbide knobbies you could have. I've picked up a couple when I was thinking of a sabot round for my falconette.

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16 hours ago, ThomasPowers said:

How do you harden mild steel?  You throw it away and replace it with an alloy that will harden.

Thanks, that looks like great advice.  I'll try mounting the bucket teeth next and see how they hold up.

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Ok, I don't have a forge just an Oxy/Act torch...but in case I get the urge to heat them up and pound on them with a hammer I'll keep them around.

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Setting up a functional forge is really easy, a hole with a fire in it and a supply of forced air has worked for thousands of years. The JABOD is a sweet charcoal forge and works a treat with coal with minimal tweaking. A side blast works better for coal than a bottom blast does with charcoal. If you have to choose one. Side blast works well with most any solid fuel.

Frosty The Lucky.

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Okay...it took some searching for me to figure out that JABOD is Just A Bunch Of Dirt, and it lead to a thread of someone building one.  Now I could use some help with the terms 'clinker' and 'tuyere'.

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Tuyere: 

"a nozzle through which air is forced into a smelter, furnace, or forge."

Clinker: "the stony residue from burned coal or from a furnace."

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I begin to get hesitant to help people over the net with possibly dangerous activities when folks seem to not be able to use a dictionary on the net. I strongly encourage you to do at least minimal due diligence on your own and refer "refractory questions" to the forums.

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