Laser cutting: advantages & disadvantages

CNC laser cutting provides a precise, versatile and fast profiling solution in metal forming design. It is ideal for intricate patterns and is extremely cost-effective.

During the cutting process, physical contact with the metal is limited to an ultra-fine laser beam. This helps eliminate the risk of material contamination and damage to the material surface, particularly beneficial when fabricating soft sheet metals or creating aesthetic products.

Other advantages of laser cutting machines include:

• CO2 and fibre lasers can create complex shapes from different materials, including mild steel, aluminium, copper and plastics, in various thicknesses
• The ability to carry out other metalworking techniques such as marking and engraving-Laser cut surfaces have less roughness or ‘burrs’ and avoid the need for secondary metal finishing which can increase costs and lengthen lead times. Smoother edges are achieved with thinner materials.
• Compared to other cutting processes the area exposed to heat during laser cutting is tiny, reducing the likelihood of warping and allowing for more precise results.

• More accurate results are achieved with thinner material thicknesses
• When cutting simple shapes in large batches, CNC punching machines can improve on production speeds.
• Less precise results compared to CNC punching when fabricating softer materials such as aluminium.
• Laser cutting tends to have a rate of high energy consumption.

CNC punching technology uses a set of punches and dies to punch parts out of sheet metal. CNC punching and laser cutting are the cutting techniques most commonly used by metal fabrication subcontractors.

• Laser cutting offers improved edge quality and can eliminate the need for the costly metal finishing processes needed for CNC punching.
• Laser cutting allows faster changeover and set up times as there is no need for bespoke tooling. Instead, a laser machine can change programmes instantaneously, and this can bring benefits to cost and turnaround time. Bespoke tooling can be expensive to store and maintain.
• Part nesting used in CNC punching is less efficient because provision is required for the punching nibble tools between the parts. Also, there are no tooling restrictions for dynamic nesting in laser cutting so multi-complex shapes can be cut on the same sheet without lengthy setup times or the need for many bespoke punch tools

Despite these limitations, CNC punching often delivers a more competitive and equally high-quality solution when fabricating simple component shapes in large batch sizes.

A significant advantage of CNC punching over laser cutting is its ability to achieve forms, e.g. tap, extrude, rib and louvre which cannot be replicated on a laser cutting machine.

As market-leading metal fabrication subcontractors, KMF delivers a versatile CNC laser cutting service. Employing the latest in laser cutting technology, including C02, Fibre Laser and Punch/Laser combination machines, we can deliver an accurate, consistent and competitive precision laser cutting service in many material types including mild steel, aluminium and coated steels.

We use Trumpf TruLaser machines, 3030 & 5030 as well as a Trumatic 6000 and 7000 laser/punch combination machines. All laser technology is complemented by an automated material storage tower, TruStore Series 3000.

The majority of leading metal fabrication subcontractors employ two types of CNC laser cutting machines, optical fibre and CO2.

Fibre laser cutting machines are members of the solid-state laser group. They create a beam using a ‘seed laser’ which is amplified by glass fibres supplied with energy via pump diodes. Fiber laser cutting is used on reflective materials, is most suited to thinner materials and provides greater electrical efficiency.

Fibre lasers can also be used for metal marking techniques as in laser engraving.

By comparison, C02 laser cutting machines are a type of gas laser that uses an electrically stimulated carbon dioxide mixture. C02 lasers can be used for a range of materials, both metal and non-metal, and deliver a fast cutting rate for thicker materials.

Each type of CNC laser cutting machine has its advantages and disadvantages and metal fabrication subcontractors often employ different laser techniques for various applications.