If you’re anything like me, when you see a chunk of metal laying around you’re instantly wondering what you can make from it. Railroad tracks are very solid chunks of steel.
So what kind of steel are railroad tracks made of?
Railroad track steel is typically 1084 or equivalent hot rolled steel. This is a medium carbon steel with 0.7% to 0.8% carbon and 0.7% to 1% manganese.
This type of steel is great for heat treating. It’s tough, through-hardening, and forgable.
Let’s go over the properties of this metal, some effective ways of working with it, as well as some good applications for the grade.
Properties of Train Track Steel
One of the noticeable features of this steel is the high manganese content. This is a requirement for good reason – it allows for deeper heat treatment.
For railroad tracks to perform well in the long term, there are two really important qualities that the steel needs to have: high wear resistance and resistance to fracturing.
The deeper heat treatment allows the steel to have higher strength properties. Basically, it’s less likely that there would be surface cracks that would propagate over time.
As you can imagine, trains are heavy and put an extraordinary amount of stress on anything below them. Depending on the size of the trains and rate of use, a track could be expected to last anywhere from 5 to 100 years.
That’s not to say that the rails are untouched for that amount of time – as the rails wear out, they can be “dressed” – a grinding process that will recondition the rounded top of the rails to restore its performance. This will get rid of any “mushrooming”, wear or deformation of the metal.
1084 steel can usually be heat treated up to 65 Rockwell C, but at that hardness it’s very brittle. A more ideal hardness is around 60-62 Rc, where the metal is sufficiently tough to resist cracking.
At that hardness, the steel has a really good wear resistance.
If you’re into charts, here are some of the general properties of the steel:
|Ultimate Tensile Strength||113,000||135,000||PSI|
|Hardness (heat treated and tempered)||50||65||Rc|
If this chart means nothing to you, here’s a quick explanation of what this means:
- Railroad tracks are hard and strong
- They’re an excellent choice for most things that need heat treating
- This is on the harder end of the “scrapyard metals” that are heat treatable – it will typically get harder than something like a leaf spring.
Here’s some more useful information about the size of the tracks:
Usually they’re designated by weight per yard. Main lines will commonly be 130 pounds per yard, whereas smaller lines could get to around 70 pounds. For very small lines, like old ones for hand carts in mines, you might find it even smaller.
This means that if you cut off a foot of main line track, it will probably weigh over 40 lbs.
Tips for Working with Railroad Track Steel
Obviously, this is pretty hard stuff. You’re not going to get too far with a hack saw.
If you do, send me a video. I’m always up for a good laugh.
So here are some tips for cutting and working with railroad tracks:
- Use either a cutting torch (ideal) or a cutoff wheel (much slower) to cut off a length to work with.
- If you’re using heat to cut off a piece, make sure you leave lots of extra stock so that you can later remove the heat affected zone (HAZ). This will really mess up your heat treating – the metal will be soft on those ends.
- If you’re not sure how much of an area this is, do a little test cut. The HAZ is the part that is discolored (usually a straw or blue color). If you do a half decent job with the torch, this zone will probably go in about half an inch max from your cut line.
- If you need to machine it, try annealing it first. Otherwise, this stuff can be nasty. Annealing can be a little bit tricky unless you can a controlled oven.
- You need to heat it up to 1500 F and then slowly cool it to 1200 F at no faster than 50 F per hour. Much easier with a programmable oven. Maybe call in a favor with a machinist buddy if you don’t have access.
- Again, for machining: don’t bother with high speed steel cutters. Technically, you could do it, but it’ll be ugly and you’ll spend way too much time dressing your tools. Go with carbide inserts that have strong geometry for tough steels.
- Grinding works great. If the track is annealed, you could even use an aggressive flap wheel on an angle grinder and remove a decent amount of material. If it’s hardened, it will be slow going.
- For forging, keep it well between 1500 and 2150 F. If it’s too cold then it’ll crack, if it’s too hot the carbon will burn out and you’ll have a miserable time with heat treating.
Variations in Steel Grade
Obviously, not all railroad track will be exactly the same grade.
This is especially true of older tracks. Now that there are better and more standardized manufacturing methods, any track that’s only a couple of decades old is likely to be a 1084 or at least be very similar.
Earlier than that, though and it could be anyone’s guess. 200 years ago, they’d make the rails with wood. It’s been steady upgrades from there.
If you’re not sure about the grade, you’ll want to test it. Actually, it’s a good idea to test it anyway before you do anything major with it, unless it really doesn’t matter. If you’re making a door stop, it really doesn’t matter.
So here’s how you test it:
Cut off a small piece, ideally with a zipcut or some other kind of cutoff disc. Don’t let the metal get red hot.
Then use a torch to heat up the metal cherry red. If you’re a pro at heat treating, you might be able to get this right by eye. If you’re like the other 99% of us, get a neodymium magnet and wrap a stiff steel wire around it so that you can hold it against the hot metal without getting your hand too close.
When the metal is at the right temperature for heat treating, it will no longer be magnetic. Don’t let it heat up much hotter than that.
Try to keep the metal at that temperature for a couple of minutes by feathering the flame back and forth.
Then dunk it in oil.
Once the metal is cool, get a file and see if it digs in. If the file bites in, then the metal is softer than the file. If the file skates across it, then the metal is harder.
This won’t tell you exactly if the track is 1084 or not, but you’ll know if it’s heat treatable.
Practical Uses of Train Track Steel
This is the fun part: What can you make with the stuff?
This is actually pretty popular metal to work with among knife makers. It’s great for forging and heat treats really well.
It can take a little bit of effort to get into a good shape for knife making, but once you do it’s a carbon steel that’s great for choppers and will definitely hold an edge.
Lots of people have also gone to town grinding these things down into small anvils. The steel really holds up well against hammering, and these little anvils can work great for fine, detailed work.
Or you could make a door stopper.
Heat Treating Information
So if the steel really is 1084, then here’s how you can treat it:
- Bring the steel up to 1450 F
- Once you’ve hit that temp, “soak” the metal for 15 to 20 minutes. Basically, just hold it at that temperature.
- Quench in warm oil.
- Temper the steel to draw the hardness back. This will help remove stresses and prevent cracking. Don’t forget this step!
- To temper the steel, let it sit in an oven at 375 degrees for 2 hours. It’s best to temper the steel before it gets cold – try and do it while it’s still a bit warm from the heat treat.
- Do a file test to make sure that it’s hardened properly. The file should skate across the metal instead of biting in.
If you’re planning on doing a bit of heat treating, it can be really nice to have a infrared thermometer to confirm the temperatures. Hardening metal can be a fickle process, especially while you’re getting the hang of it.
It can be hard to find one that will read temperatures high enough for heat treating, and at this range they get a bit pricier. Either way, it’s a good tool to have. This one on Amazon will do the trick for you.
Do you have any comments? Have you made something interesting with railroad tracks? Post it in the comments below!