Types of Steel for Blacksmithing: Carbon Steel

Types of Steel for Blacksmithing: Carbon Steel

According to the World Steel Association, there are more than 3500 different grades of steel with different physical, chemical, and environmental properties. And 75% of modern steels have been developed in the past 20 years. So there are a lot of different types of steel—what does it all mean and how do you know which one(s) you want?

What is Steel?

Let’s start at the beginning. Steel is an alloy of iron and less than 2% carbon. It may also contain less than 1% of manganese, silicon, phosphorus, sulphur, oxygen, and other alloying elements. Alloys that are more than 2.1% carbon are cast iron.

Types of Steel

The American Iron & Steel Institute (AISI) categorizes steel into four broad categories:

1. Carbon Steels

Probably the biggest category of steel, and the most popular for blacksmithing, is the carbon steels. The level of their carbon content breaks them down into three smaller categories: low carbon/mild steels (up to 0.3% carbon), medium carbon steels (0.3-0.6% carbon), and high carbon steels (more than 0.6% carbon).

2. Alloy Steels

Alloy Steels contain alloying elements to manipulate it’s properties, such as ductility, hardenability, corrosion resistance, formability, strength, or weldability. Alloying elements can include aluminum, chromium, copper, manganese, nickel, silicon, and/or titanium.

3. Stainless Steels

Stainless steels are alloys that contain 10-20% chromium. With 11% chromium, steel becomes about 200 times more resistant to corrosion.

4. Tool Steels

Tool steels contain various quantities of cobalt, molybdenum, tungsten, and/or vanadium. These alloying elements improve heat resistance and durability, which makes them great for tools.

Carbon Steel for Blacksmithing

The vast majority of blacksmithing uses low and medium carbon steels. High carbon steel, sometimes called “carbon tool steel,” is very hard, and difficult to bend or weld; it gets very brittle once it’s been heat-treated.

You can buy steel, or you can find and recycle. I prefer the later.

Recycling Steel

We started with recycling steel because it’s free, but it works so well … we still don’t really buy much steel. Some good sources to keep an eye out for:

  • Rebar
  • 55 gallon drums
  • Braided cables
  • Lawnmower blades
  • Railroad spikes
  • Vintage tools, especially metal files
  • Leaf springs, and other old car springs

Junk yards, railroad tracks, that weird dead-end road where people dump stuff, the dark corner of your friends’ garages and basements … all good places to find scrap steel. You’ll be surprised once you start looking.

Buying Stock Steel: The Grade System Breakdown

If you want to buy steel, you’ll quickly notice there are a lot of numbers involved: the carbon steel grade system. It’s been around since the 1940s. Here’s how it works:

There are four or five digits involved, and sometimes alpha characters to indicate special characteristics.

The first number tells you the general category of steel:

  • 1 = carbon steel
  • 4 = molybdenum steel
  • 5 = chromium steel
  • 6 = chrome vanadium steel
  • 8 = nickel chromium molybdenum, steel
  • 9 = silicon manganese steel

The second number indicates the presence of other elements that affect the steel. Zero is the most common, and just means there are no other elements. A 1 in the second position means sulfur has been added. When other alloys are added, a letter is included after the second digit:

  • L = lead (improves machinability)
  • B = Boron (hardens)

The last two numbers indicate the percentage of carbon content in the steel. XX = .XX% steel. The carbon contents can’t be controlled, during manufacturing, to an exact percentage, so the number shown is the nominal percentage.

So a 1095 steel is a carbon steel, with no additional alloys, that is 0.9 to 1.0% carbon.

Buying Stock Steel: Which Do I Want?

1050 to 1095 steels are good options, especially if you’re just getting started. They’re softer than tool steels, so they won’t destroy an amateur grinder. 1095 is cheaper, because it doesn’t wear as well and it’s not as tough as a 1050, but it gets the job done.

1095 high-carbon tool steel is a good option. It holds a great edge and is relatively easy to sharpen.

Ultimately, though, there are a lot of factors involved—your setup, your project, etc.—so be prepared to experiment a little bit until you figure out what works best.

Your Turn: What Do You Use?

If you’ve been smithing, what do you use? What do you buy? What do you recycle? What did we miss? Leave a comment and let us know what’s working for you.

 

18 comments

Caterpillar head bolts, semi-truck u-bolts. Better have a good hot Forge and leave your skirt at the house, because is this stuff is hard.. happy hammering

Spark testing is a common method. Run your steel on the grinder & look at the sparks. Long, profuse sparks with ‘stars’ is great. Very few short stars means no good, probably not hardenable. This won’t tell you exactly what type of steel you have, though you could compare your sparks to known grades you already have. But generally,
buttloads of sparks = joy,
very few= no good.
None at all means you have a piece of wood, you jackass!

I live about half a mile from w rail road, so I get plenty of spikes, old rails, hinge pins, track plates. All good stuff but I find the spike is the easiest to work with.

I usually buy AISI 1055 and 1095, we also have a ton of EN45 flying around here in London. I look for scrap leaf springs all the time, but I never find any going for free, if you can find leaf springs, grab them up.

I am getting ready to start blacksmithing and just wanted to say what a great article! During the class I took they kept talking about cast iron, tool steel, mild steel and I kept thinking how am I going to know the difference. This goes a long way toward helping. Quick question- if you find a piece of scrap steel but it’s rusted is that a big deal or do you just grind it off and use it?

I would take the time to clean it up it will make it easier to see if you are getting it to hot and help you in the long run of thing but that is just how I feel

I found one of the most desissyfying pieces of steel comes 2 to a car or preferably a truck. Find them and you have a King of a deal. But, shy of an autohammer you will need lots of heat, time and determination.

Interesting and infirmitave article. I hav ed been smithing for years. Have degrees in metallurgy and machining. Still most of my steel is recycled 5160. Also have chrome moly and Vega pieces . Loads of fun and a great workout.

Thanks guys, keep up the good work! I am so pleased with this product. I didn’t even need training. Types of Steel for Blacksmithing is both attractive and highly adaptable.

So what dose the 80 in 1080 steel stand for I know that the 10 means that it is carbon steel with no other elements like copper but what about the 80

That would mean it has .80% carbon in the metal, the last 2 digits indicate a .XX% so you just put a period before them.

Hey Brandon. It really depends on what you want to do with it. I believe the majority of that steel is made from an alloy known as chromoly. Or 4130 carbon steel. Typically (for a knife) , you want your carbon count to be 0.5/0.7-1 percent. The 4130 has a pretty high carbon count at 30%. It’s not awful for a blade. Not the best either. Now, if you’re looking to just have steel for forging…you should have no problems with that steel for every day kinda forging. What’s nice about that alloy is you can quench it in water without destroying your piece. Hope that helps.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.