12L14 vs. 1018 Steel: Which One Should You Use For Your Part?

Are you trying to choose the right grade of carbon steel for your machined part?

There’s a wide range of steel alloys, but if you look at the elements in each look nearly identical. But, each steel alloy has different properties and is ideal for different part designs.

12L14 steel and 1018 steel are two commonly used steel alloys.

This post will explain the differences between these two metals and help you choose which one is best for your next project.

What are the big differences?

The biggest difference between 12L14 and 1018 steel is the hardness and machinability.

These two alloys have similar amounts of iron, carbon, and manganese. What makes them different is that 12L14 steel has more sulfur and lead. Adding these elements–even in small quantities–makes the metal much easier to machine. The added sulfur also makes the alloy harder to weld, and heat treating the parts is less effective compared to 1018.

12L14 steel is considered a free machining alloy. 12L14 is also stronger than 1018 and has a much higher tensile strength.

Free machining steel alloys are used when the part design is more complex. The added elements make the metal require less power to machine, improve the surface finish, and make smaller metal chips.

1018 carbon steel can still be machined. It just requires more effort, and is better for parts with a simpler design that requires fewer cuts and slotting.

Element	1018 Steel	12L14 Steel
Iron	98.81-99.26%	97.91 - 98.7%
Carbon	0.18%	0.15%
Manganese	0.60-0.90%	0.85 - 1.15%
Phosphorous	0.04%	0.04 - 0.09%
Sulfur	0.05%	0.26 - 0.35%
Lead	0.0%	0.15 - 0.35%

12L14 Steel

12L14 steel is the most popular free-machining alloy steel. This metal is ideal for parts that require more complex machining and tight tolerances. The added lead and sulfur allows 12L14 to be machined quickly and efficiently, and makes a smooth finish easily achievable.

12L14 steel is often used as the standard machining cost factor that other materials are compared to. If a metal is easier and cheaper to machine, the cost factor would be less than 1.0. And if it’s more difficult to machine, the machining cost factor will be greater than 1.0. This steel shouldn’t be used for parts that will be welded because of the added sulfur.

12L14 doesn’t respond well to heat treatment, but other secondary operations like nickel plating can be done effectively.

Common 12L14 Parts

Bushings
Shafts
Inserts
Couplings
Fittings

1018 Steel

1018 steel is a general purpose low-carbon steel alloy. Compared to 12L14 steel, 1018 has a machining cost factor of 2.4. It can be machined, but is better for rivets, pins, and spacers, which require simpler machining. Unlike 12L14, this steel alloy is ideal for parts that require a strong weld, forming, heat treating, or surface hardening.

1018 steel produces exceptional welds that don’t require pre or post-heating processes.

1018 steel is also one of the least expensive alloys. Since most steels are relatively low-cost, this factor isn’t the most important unless very high quantities of parts are needed. The higher cost of machining also lowers the impact of the lower raw material cost.

Common 1018 Parts

Rivets
Spacers
Shafts
Gears
Pins

Which steel alloy should you use?

So, which steel alloy should you use?

The first thing you should consider is the design of your part. If your part is more complex, a free machining alloy will be better. A simple pin or spacer that’s easy to machine can use a regular steel alloy.

Next, consider the finish you want on your part. 12L14 steel is more limited, generally to plating, while 1018 steel can be heat treated and hardened. And lastly, if the part will be welded, 1018 is the better choice.

You can visit our material page to compare the different options for your next CNC machining project. If you have any other questions about choosing the right materials, reach out to our team.