Buyer’s Guide: Processing Tips

How To Improve the Quality of Laser Cutting

To improve the quality of precise cutting by a pulsed laser, please refer to laser marking and engraving, or micromachining. We generalize the laser cutting quality key points and available parameters first, then outline some tips for metal cutting by CW laser in the following table:

Laser cutting quality observation points

  • The width or kerf
  • No hard removable slag or residual
  • Perpendicularity of kerf
  • Surface roughness of kerf

Possible process parameters

  • Laser sources: CW mode or Pulse mode, Power and Frequency
  • Laser beam focus position
  • Assisted gas: type selection, and the pressure and/or volume control
ModeSymbolApplicationExamples
CW (continuous wave)
  • Cutting at low pressure
  • Regular Cut
  • Cutting at high pressure
  • Structural steel with O2
  • Aluminum with N2
  • Stainless steel with N2
  • Constant power for relatively precise cutting
GP (gate pulse)
  • Drilling
  • Tiny patterns
  • Holes in the pattern
  • The diameter of holes is half of the thickness of the workpiece
  • Fine patterns
SP (super pulse)
  • drilling
  • Highly reflective material
  • Copper with N2
  • Stainless steel with O2
  • Heat resistant steels with O2
  • Inox +
  • Increasing laser power by using 100%CW and HP
HP (high-energy pulse)
  • Drilling
  • Zinc Steel with O2
  • Fast drilling for thick plate, Small amount of debris

Structural steel: Cutting with O2

DefectsPossible ReasonSolution
Burr-free, uniform cutting ripples
  • Power is suitable
  • Feed rate is suitable
Large offset at the bottom
Wider kerf
  • Feed rate is too fast
  • Laser power is too low
  • Pressure is too low
  • Focus is too high
  • Decreasing feed rate
  • Increasing laser power
  • Increasing pressure
  • Lowering focus
Burr-like slag at the bottom, easy to remove
  • Feed rate is too high
  • Pressure is too low
  • Focus is too high
  • Decreasing feed rate
  • Increasing pressure
  • Lowering focus
Metal Burrs that are connected together can be removed together as a single piece
  • Focus is too high
  • Lowering focus
Burrs are difficult to remove at bottom
  • Feed rate is too high
  • Pressure is too low
  • Focus is too high
  • Gas impure
  • Decreasing feed rate
  • Increasing pressure
  • Using gas with high purity
  • Decreasing focus
Burrs only exist at one side
  • Incorrect nozzle centering
  • Defective nozzle
  • Correct nozzle centering
  • Change nozzle
Material spills out on surface
  • Laser power is too low
  • Feed rate is too high
  • Press the stop button immediately to prevent molten material from splashing onto the focusing lens
  • Increasing laser power
  • Decreasing feed rate
Inclined plane cutting
  • Polarized lens are not installed correctly, or are defective
  • Polarized lens are installed at the position of the deflection lens
  • Check polarized lens
  • Check deflection lens
Blue plasma, the workpiece is not being cut through
  • Incorrect gas in use (N2)
  • Feed rate is too high
  • Laser power is too low
  • Press the stop button immediately to prevent molten material from being splashed onto the focusing lens
  • Use oxygen as cutting gas
  • Increasing laser power
  • Decrease feed rate
Cutting surface is not precise
  • Pressure is too high
  • Nozzle damage
  • The diameter of the nozzle is too large
  • Material is incorrect
  • Decreasing laser power
  • Changing nozzle
  • Using a material with a smooth surface
Burr-free uniform cutting ripples
Inclined cutting angle
  • Feed rate is too high
  • Decreasing feed rate
Crater generation
  • Pressure is too high
  • Feed rate is too slow
  • Focus is too high
  • Rust on the surface
  • Workpiece is overheated
  • Material impurities
  • Decreasing pressure
  • Increasing feed rate
  • Lowering focus
  • Using material with higher quality
Very rough cutting surface
  • Focus is too high
  • Pressure is too high
  • Feed rate is too low
  • Workpiece is overheated
  • Lowering focus
  • Decreasing pressure
  • Increasing feed rate
  • Cooling material

Stainless Steel: High-Pressure cutting with N2

DefectsPossible ReasonSolution
Small regular drip-like burrs
  • Focus is too low
  • Feed rate is too high
  • Raising focus
  • Decreasing feed rate
Irregular drip like burrs on both sides
Surface discoloration of large plate
  • Feed rate is too low
  • Pressure is too low
  • Workpiece is over-heated
  • Increasing feed rate
  • Lowering Focus
  • Increasing pressure
  • Cooling material
Irregular and slender burrs only on one side of cutting edge
  • Incorrect nozzle centering
  • Focus is too high
  • Pressure is too low
  • Velocity is too low
  • Correct nozzle centering
  • Lowering focus
  • Increasing pressure
  • Increasing velocity
Yellowed cutting edge
  • Nitrogen contains oxygen impurities
  • Using nitrogen gas source with higher purity
Plasma formation on the straight section
  • Feed rate is too high
  • Laser power is too low
  • Focus is too low
  • Press the Stop button immediately to prevent molten material from splashing onto the focus lens
  • Decreasing feed rate
  • Increasing laser power
  • Raising focus
Dispersion of laser beam
  • Feed rate is too high
  • Laser power is too low
  • Acceleration is too high
  • Decreasing feed rate
  • Increasing laser power
  • Raising focus
Plasma formation at the corner
  • Angle tolerance is too high
  • Modulation is too high
  • Acceleration is too high
  • Decreasing angle tolerance
  • Decreasing modulation
  • Decreasing acceleration
Dispersion of laser beam at the beginning
  • Molten material failed to remove due to higher acceleration and lower focus
  • Decreasing acceleration
  • Raising focus
Rough kerf
  • Nozzle is broken
  • Lens is dirty
  • Changing nozzle
  • Cleaning lens(if needed)
Material spill our of surface
  • Power is too low
  • Feed rate is too high
  • Pressure is too high
  • Press the stop button immediately to prevent molten material from splasing onto the focus lens
  • Decreasing feed rate
  • Increasing laser power
  • Raising focus
  • Decreasing pressure

Aluminum alloy: high-pressure cutting with N2

DefectsPossible reasonsolution
Irregular and slender burrs on both sides are difficult to remove
    • Focus is too high
    • Pressure is too low
    • Feed rate is too low
  • Lowering focus
  • Increasing pressure
  • Increasing feed rate
Irregular and long burrs on both sides that can be manually removed
  • Feed rate is too low
  • Increasing feed rate
Rough kerf
  • Nozzle is broken
  • Feed rate is too high
  • Raising focus
  • Increasing feed rate
Regular and tiny burrs that are difficult to remove
  • Focus is too low
  • Feed rate is too high
  • Raising focus
  • Increasing feed rate
Plasma formation on the straight sections
  • Focus is to low
  • Feed rate is too high
  • Raising focus
  • Increasing feed rate
Dispersion of laser beam
  • Feed rate is too high
  • Decreasing feed rate
Plasma formation at the corner
  • Angle tolerance is too high
  • Modulation is too high
  • Acceleration is too high
  • Decreasing angle tolerance
  • Decreasing modulation
  • Decreasing acceleration
Plasma formation at the corner
  • Angle tolerance is too high
  • Modulation is too high
  • Acceleration is too high
  • Decreasing Angle tolerance
  • Decreasing modulation
  • Decreasing acceleration
Dispersion of laser beam at the beginning
  • Focus is too low
  • Feed rate is too high
  • Raising focus
  • Increasing feed rate
Material spill out on the surface
  • Laser power is too low
  • Feed rate is too high
  • Press the stop button immediately to prevent molten material from splattering onto focusing lens
  • Increasing laser power
  • Decreasing feed rate

For CLC equipment owners, if you have an urgent project on hand and cannot resolve your issue after reading the above tips, please do not hesitate to contact us today, we would be honored to get the opportunity to help resolve your processing issue.

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