Carbon Steel

Carbon Steel Cold Finish (CF)

Cold finished carbon steel bars are processed through a series of cold drawing, turning, grinding, and polishing steps to improve their dimensional accuracy, surface finish, and mechanical properties.

Characteristics:

  • Higher Strength & Hardness: Due to strain hardening from the cold-working process.
  • Improved Surface Finish: Smoother and more uniform compared to hot-rolled steel.
  • Better Dimensional Accuracy: More precise tolerances compared to hot-rolled bars.
  • Improved Machinability: Less scale and surface defects, making it easier to machine.
  • Reduced Internal Stresses: Often stress-relieved to prevent warping during machining.

Common Grades of Cold Finished Carbon Steel:

  • 1018: Low carbon, excellent weldability, good machinability.
  • 1045: Medium carbon, better strength and hardness than 1018, used for shafts and gears.
  • 1144 (Stressproof®): High-strength, stress-relieved, excellent machinability.
  • 12L14: Free-machining steel with added lead for enhanced machinability.

Common Applications:

  • Shafts, axles, pins, fasteners
  • Structural components
  • Gears, bolts, and machine parts

Precision Ground Bars

Precision ground bars are steel bars that have undergone additional grinding operations to achieve extremely tight tolerances and high surface finish.

Characteristics:

  • Ultra-Precise Tolerances: Often held to ±0.0005” or better.
  • Superior Surface Finish: Achieved through centerless grinding.
  • Straightness & Roundness: Ideal for precision applications.
  • Low Friction: Smooth surface reduces wear in moving applications.

Common Grades of Precision Ground Bars:

  • 1018 Carbon Steel: General-purpose low-carbon steel, good for precision machining.
  • 1045 Carbon Steel: Higher strength and wear resistance, often used for shafts.
  • O1 & A2 Tool Steel: Precision ground for tooling applications.
  • 4140 Alloy Steel: Good strength, toughness, and wear resistance.

Common Applications:

  • Precision shafts and rods
  • Linear motion components
  • Guide rails
  • Die and mold components
Carbon steel is classified into different grades based on its carbon content and additional alloying elements. The main categories of carbon steel grades are:

Low Carbon Steel (Mild Steel)

  • Carbon Content: 0.05% – 0.30%
  • Properties: Soft, ductile, good weldability, and machinability.

  • Common Grades:

    • A36 – Structural steel, used in construction.
    • 1010, 1018, 1020 – Common mild steels used in automotive, machinery, and general applications.

Medium Carbon Steel

  • Carbon Content: 0.30% – 0.60%
  • Properties: Stronger than low-carbon steel, better wear resistance, but less ductile and harder to weld.

  • Common Grades:

    • 1040, 1045 – Used in shafts, axles, gears, and structural applications.
    • 1144 (Stressproof®) – Higher machinability and fatigue resistance.

High Carbon Steel

  • Carbon Content: 0.60% – 1.00%
  • Properties: Very hard, high strength, wear-resistant, but brittle.

  • Common Grades:

    • 1095 – Used in knives, springs, and cutting tools.
    • 1060, 1075, 1080 – Used for blades, automotive components, and high-strength wires.

Ultra High Carbon Steel

  • Carbon Content: 1.00% – 2.00%
  • Properties: Very hard, brittle, used in specialized applications.

  • Common Grades:

    • W1, W2 – Tool steels, knife blades, and cutting tools.

Alloying Elements in Carbon Steel

  • Manganese (Mn): Improves hardness and strength.
  • Silicon (Si): Enhances strength.
  • Sulfur (S) & Phosphorus (P): Can reduce toughness but improve machinability in some cases.

Carbon Steel Applications

  • Low Carbon Steel: Structural beams, automotive panels, pipes.
  • Medium Carbon Steel: Shafts, gears, railway tracks.
  • High Carbon Steel: Springs, knives, wear-resistant tools.
  • Ultra High Carbon Steel: Tool steels, specialized applications.