Steel is an alloy of iron and carbon, preferred for fabricating parts that demand high strength, toughness, and durability. Steel alloys are composed of elements like manganese, nickel, and others added in addition to carbon to improve properties like strength, hardness, and heat or corrosion resistance. Most steel alloys can be case hardened, providing excellent machinability.

At Plethora, we offer a full assortment of steel alloys for custom steel prototyping services, each offering unique benefits. Customers trust us to provide the highest quality parts with tight tolerances and our 3-axis and 5-axis milling and turning capabilities. Steel is one of the most popular machined materials used in many industries:

  • Construction
  • Automotive
  • Aerospace
  • Transportation
  • Defense
  • Marine
  • Medical instruments
  • Household appliances
  • Security

CNC milling machine for steel prototyping


Advantages of Using Steel for Your Next Component

Different steel types offer many advantages as compared to their other metal counterparts for component designs. These includes:

  • Excellent tensile and yield strength
  • Good thermal conductivity
  • Wear and tear-resistant
  • Long service life
  • Easy weldability than metal like aluminum
  • Cost-effectiveness and recyclable

These properties can differ based on the carbon content in the steel. The table below will guide your selection of carbon steel as per the requirement for your application.

Properties Low carbon steel 0.05 to .0.30% Medium carbon steel 0.30 to 0.60% High carbon steel 0.60 to 1.00%
Weldability High Medium to low Low
Hardenability Low High to medium High
Machinability Low High to medium/low Low
Workability High High to medium/low Low
Wear resistance Low Medium High
Strength to weight ratio Low High to medium High
Cost Low Medium High

Machining with Different Steel Types

Steel typically has a small amount of carbon (usually less than 2%), with chromium and molybdenum elements added to define its properties. Plethora offers 1018, 1020, 1040, 1045, 1117, 1144, 12L14, 4130, and 4140 steel for machining applications. 

1018 Steel

  • 1018 steel is a commonly available mild/low carbon steel with excellent machining properties.
  • The steel has good strength, toughness, ductility and provides excellent weldability.
  • 1018 steel is suitable for crimping, bending, or forging processes.
  • Ideal for parts like anchor bolts, fasteners, gears, shafts, and other machinery parts.  

1020 Steel

  • 1020 steel is low carbon content steel with good machining properties.
  • The steel provides high strength, ductility, and weldability.
  • 1020 steel can be used for milling, turning, drilling, and tapping applications to produce parts such as axles, shafts, gears, and spindles. 

1040 Steel

  • 1040 steel has a relatively higher carbon content of 0.40% compared to other low carbon alloys.
  • The high carbon content provides good machinability to the steel.
  • The steel is weldable and compatible with any welding methods.
  • Used for applications such as couplings, crankshafts, fasteners, and cold-headed parts.

1045 Steel

  • 1045 steel has a high carbon content of 0.45% and has medium tensile strength.
  • The steel has good machinability and strength due to its high carbon content.
  • 1045 steel can be used for milling, turning, tapping, and drilling applications. Some examples include gears, shafts, pins, sockets, axels, bolts, and crankshafts.

1117 Steel

  • 1117 steel has a low-carbon and high-manganese, and sulfur content.
  • It provides excellent machinability for applications that require a tight tolerance and smooth surface finish.
  • Used for manufacturing parts such as gears, shafts, or studs.

1144 Steel

  • 1144 steel has medium carbon content and high manganese and sulfur content. 
  • Additional molybdenum, nickel, chromium, copper, silicon, and aluminum content supports in providing high tensile strength.
  • It has good machinability and wear-resistant properties.
  • Some examples of parts manufactured include gears, shafts, and spindles 

12L14 Steel

  • 12L14 steel is a standard re-sulfurized and re-phosphorized steel.
  • The added sulfur, phosphorus, and lead improve machinability and ductility.
  • It has low carbon content compared to other steel, thus comparatively low strength.
  • Used in high-speed machines for producing fittings and valves.

4130 Steel

  • 4130 steel is low carbon steel with additional chromium and molybdenum content for adding strength.
  • The steel has good tensile strength, toughness, machinability, and weldability.
  • It supports any type of commercial welding method.
  • 4130 steel is ideal structural application steel for buildings. Some other applications include vehicle parts, bearings, and gears

4140 Steel

  • 4140 steel is known for its high tensile strength, toughness, wear-resistance, and versatility.
  • A low carbon “Chromoly” steel.
  • Although not as much as stainless steel, Chromoly steel has corrosion resistance properties due to the addition of chromium.
  • 4140 steel’s good ductility, strength, and wear resistance make it suitable for applications such as gears, nuts, bolts, shafts, axels, and other machinery parts.

The mechanical properties of each steel type offer unique advantages for your applications.

  1018 Steel 1020 Steel 1040 Steel 1045 Steel 1117 Steel 1144 Steel Steel 12L14 Steel 4130 Steel 4140
Tensile strength, ultimate (psi) 63800 57249 89900 81900 68900 108000 78300 81200 95000
Tensile strength, yield (psi) 53700 42748 60200 45000 58000 89900 60200 66700 60200
Elastic modulus (ksi) 29700 29000 27557- 30458 29000 27557 - 30458 27557 - 30458 27557 - 30458 27557 - 30458 27557 - 30458
Shear modulus (ksi) 11600 11600 11600 11600 11600 11600 11600 11600 11600
Poisson’s Ratio 0.290 0.290 0.27 - 0.30 0.290 0.27 - 0.30 0.27 - 0.30 0.27 - 0.30 0.27 - 0.30 0.27 - 0.30
Elongation at break (in 50 mm) 15% 36.5% 25% 16% 15% 10% 10% 21.50% 25.70%

Key Steel Applications for Component Designs

There are several key reasons to pick steel over aluminum for a custom prototype. Steel is much stronger and less expensive. Some examples of applications that leverage the properties and advantages of steel include:

  • Transportation industry: Uses steel parts for trucks, ships, trains, and cars, including frames and wheel covers. Industry decision-makers prefer steel for its low cost, recyclability, and formability.
  • Packaging industry: Steel containers store and move products protecting them from exposure to air, water, and light that may degrade the quality.
  • Defense industry: Many mechanical parts that require close tolerances and precision use 12L14 steel. Components that need less ductility are also ideal, including many hand-held instruments. Manufacturing defense industry parts require ISO 9001 certification
  • Construction industry: Steel adds strength and integrity to the construction of buildings and infrastructures. Reinforcement steel often augments other materials such as concrete.