COLD DRAWN BAR (CDB)

COLD DRAWN BAR

Cold Drawn Bar is made from SBQ (special bar quality) HR bar.  It is drawn through a die reducing the cross-sectional area of the bar, and giving it a smooth ‘drawn’ finish.  Depending on the shape of the die, the finished product can have a round, hexagonal, square, or flat cross section.  Cold drawn bars have greater size accuracy, straightness, and increased tensile and yield strength, as well as improved machinability. In addition to standard cold drawn bars, it can be supplied as turned and polished, turned ground and polished and drawn ground and polished.

Cold Drawn Steel Product Features

  • Improved Size and Section / Reduces machining losses
    • Tighter size & section tolerances
    • Dimensional consistency within each bar
    • Dimensional consistency from bar to bar
  • Improved Steel Surface Finish / Reduces surface machining & improves quality
    • Cold drawn Steel
    • Ground and polished steel
    • Surface Improvement (Shaving or turning to produce Defect Free surface)
  • Improved Straightness / Facilitates automatic bar feeding
  • Increased Mechanical Properties / Can reduce the need for hardening
    • Yield strength
    • Tensile strength
    • Hardness
  • Improve Machinability and Productivity / Enables higher machining feeds & speeds and improved machined finish.
    • Increased machining rates
    • Longer tool life
    • Improved yield
  • Improved Formability / Improves response to spheroidization
    • Cold Drawn and Annealed
  • Improved Cost Effectiveness / Optimizes machinability and reduces yield losses
    • Production of Precision Shapes to Precision Tolerances

1018 COLD DRAWN BAR
CD 1018 is a low carbon steel with a medium manganese content. Has good case hardening properties, fair machinability and is excellent for cold bending and forming operations

1045 COLD DRAWN BAR
CD 1045 bar is a medium carbon range steel that offers better mechanical property advantages over 1018 and other lower carbon steels. It has good heat treatment response and fair welding characteristic

12L14 COLD DRAWN BAR
12L14 –12L14 is a standard resulfurized and rephosphorized grade carbon Steel, and a free machining steel. The added lead to the chemical composition provides improved machinability

STRESSPROOF TM COLD DRAWN BAR
Typical applications are keyed shafts, racks, motor shafts, mandrels, bushings, and kingpins.

The Cold Drawing Process for Steel Bars

The Cold Drawing Process for Steel Bars

  • Raw Stock: Hot rolled steel bar or rod coils are used as raw material. Because the hot rolled products are produced at elevated temperatures (1700 – 2200 Deg. F. i.e. hot rolling), they generally have a rough and scaled surface and may also exhibit variations in section and size.

  • Cleaning: Abrasive scale (iron oxide) on the surface of the hot rolled rough stock is removed.

  • Coating: The surface of the bar or coil is coated with a drawing lubricant to aid cold drawing.

  • Pointing: Several inches of the lead ends of the bar or coil are reduced in size by swaging or extruding so that it can pass freely through the drawing die. Note: This is done because the die opening is always smaller than the original bar or coil section size.

  • Drawing: In this process, the material being drawn is at room temperature (i.e. Cold-Drawn). The pointed/reduced end of the bar or coil, which is smaller than the die opening, is passed through the die where it enters a gripping device of the drawing machine. The drawing machine pulls or draws the remaining unreduced section of the bar or coil through the die. The die reduces the cross section of the original bar or coil, shapes the profile of the product and increases the length of the original product.

  • Finished Product: The drawn product, which is referred to as Cold Drawn or Cold Finished, exhibits a bright and/or polished finish, increased mechanical properties, improved machining characteristics and precise and uniform dimensional tolerances.

  • Multi-Pass Drawing: The cold drawing of complex shapes/profiles may require that each bar/coil be drawn several times in order to produce the desired shape and tolerances. This process is called multi-pass drawing and involves drawing through smaller and smaller die openings. Material is generally annealed between each drawing pass to remove cold work and to increase ductility.

  • Annealing: This is a thermal treatment generally used to soften the material being drawn, to modify the microstructure, the mechanical properties and the machining characteristics of the steel and/or to remove internal stresses in the product. Depending on the desired characteristics of the finished product, annealing may be used before, during (between passes) or after the cold drawing operation, depending on material requirements.