Tesko Laser Division - metal cutting comparison Tesko Laser Division - photos
tips navigation

Comparison of primary metal cutting processes

Tesko Laser Division was formed in 1995 to handle the high tolerance metal cutting that can be achieved using lasers. Depending on the individual needs of a customer, many different metal cutting technologies have been required. We operate a number of Mitsubishi lasers for customer and internal metal cutting, but certain jobs may require other metal cutting systems. Each of the major metal cutting systems has inherent advantages and disadvantages.

Cutting metal is a complex and lengthy task, particularly when the metal cutting job calls for a tight tolerance or an odd shape that can’t be cut using traditional sawing. Then, metal processors or fabricators like Tesko select from four cutting systems. There is a fifth system that combines laser cutting and water jet cutting, but we will not describe this hybrid system. The primary metal cutting systems include:

*

Laser cutting

*

Oxyfuel (flame) cutting

*

Plasma arc cutting

*

Water jet cutting


Laser cutting process

Description

Laser cutting systems have long had the reputation of cutting component parts with less than a 0.005" tolerance. In gas lasers, CO2 is mixed with other gases, helium and nitrogen, to form a lasing medium. Yttrium-aluminum-garnet (YAG) crystals containing neodymium ions are used as the lasing medium in solid-state lasers.

Read about the benefits of the laser cutting process.

Advantages of laser cutting

Lasers cutting is the best metal cutting system if producing a precise cut and creating the narrowest heat-affected zone are major concerns. Laser cutting systems can one-inch thick carbon materials and up to a half-inch thick specialty metals. Laser cutting systems typically use less consumables plasma or oxyfuel cutting systems. Precision capabilities continue to improve.

Disadvantages of laser cutting

Laser systems typically have a higher capital cost than plasma, oxyfuel, and waterjet systems. They are not normally capable of cutting material thicker than 0.5 inches and have difficulty cutting reflective metals like aluminum and copper, where a major portion of the laser energy can be reflected away form the cut.

Back to top

Oxyfuel (flame) cutting process

Description

Previously, metal processors like Tesko only used oxyfuel for cutting carbon steel. Today, oxyfuel technology is still the principal process for cutting metal plate for most metal processors. This process uses gases, acetylene, and oxygen to produce a controlled flame.

This process is an excellent choice for end-users requiring inexpensive cutting through carbon steel and most alloys. Oxyfuel cutting is easily capable of producing near-net shapes. But, oxyfuel cutting creates a heat-affected zone (HAZ) around the cut that must be removed by additional machining. It is possible to remove the HAZ through an annealing process after the cutting is finished.

Read details about the oxyfuel/flame cutting process.

Advantages of Cutting Using Oxyfuel

Oxyfuel cutting employs multiple-torch capability that is advantageous in high production runs. Oxyfuel cutting is an excellent choice for metal cutting that will be followed by machining activities since it often requires secondary operations to produce a satisfactory finished product.

Disdvantages of Cutting Using Oxyfuel

Oxyfuel cutting is slower than the other cutting systems and materials cut by oxyfuel are easy to spot since they display a large heat-affected zone. When a processor is looking to be able to hold tight tolerances on the cut, they will more likely select plasma, water jet, or the laser cutting processes over oxyfuel cutting. Oxyfuel cutting is just not capable of holding the tight tolerances other metal cutting processes can.

Back to top

Plasma arc cutting process

Description

Plasma arc cutting (PAC) may be the favored cutting technology for many metal processors, fabricators, service centers, and toll processors. However, historically, plasma cutting was considered to be a low cost, low tolerance cutting process. Plasma arc cutting uses a high-speed electrically charged gas jet to cut the metal. Plasma cutting is often performed at extremely high temperatures, sometimes reaching 50,000° Fahrenheit. Currently, PAC is capable of cutting metal plate up to 6.0" thick.

Plasma arc cutting system components routinely include a cutting torch, a DC power supply, a cutting gas supply, a control system, a coolant system (usually water or air) for the torch and torch parts, and leads that connect the torch, power, gas, and coolant with each other.

A variation, water-shielded PAC, costs less to operate since water is cheaper than gas. Water shielding has a number of advantages. It reduces both top-edge material rounding and the amount of irritating smoke and fumes generated when cutting without the water.

There is an elevated level of interest in high-tolerance PAC, sometimes also known as high-definition or fine-plasma cutting. High-tolerance PAC can be used to cut metals from ~0.035" to 0.375" thick. Some process users are reporting that high-tolerance plasma arc cutting produces a cut quality rivaling that of laser cutting and that it can be produced with less cost. Long-term use will bear out or refute these claims.

Read details about the plasma arc cutting process.

Advantages of plasma cutting

Plasma cutting is faster than oxyfuel cutting and is capable of cutting thicker materials. If cost is a key consideration, it is typically less costly than both than the laser and water jet cutting processes.

Plasma cutting systems using nitrogen can easily cut stainless steel, aluminum, and nickel. Systems using oxygen are more appropriately used to cut carbon products.

Disadvantages of plasma cutting

Plasma cutting creates a large heat-affected zone in the area surrounding the cut. Cutting materials under-water cutting minimizes the size of the heat-affected zone. Dross, the resolidified metal that forms at the bottom of the cut, is a potential issue for processors using plasma cutting since it frequently forms during plasma cutting.

Back to top

Abrasive water jet cutting process

Description

Water jet cutting machines pressurize a stream of water up to 60,000 pounds per square inch. This makes the water strong enough to cut many metals. Abrasive water jet systems introduce an abrasive, usually garnet, into the water stream as it leaves the nozzle. Combining the high-pressure water with the abrasive produces a stream that can cut more materials than the plain water jet without the abrasive additive. Manufacturers often develop water jets with the head submerged in a water table to reduce the noise produced by this process.

Read details about the water jet cutting process.

Advantages of water jet cutting

Water jet cutting systems cost less than laser cutting machines. Additionally, water jet cutting produces little heat-affected zone reducing the need for some secondary finishing. They are well suited for high-performance metals.

Disadvantages of water jet cutting

Water jet technology cuts slower than both plasma and oxyfuel cutting processes, reducing material processing productivity. Additionally, water jet technology has a higher entry cost than plasma or oxyfuel cutting machines.

Back to top

Deciding which metal-cutting system is best

There are so many variables to be considered when making a decision on the right cutting system to use, it is often a difficult analysis. The metal processor and, to some degree the end-user of the material, must consider at least some of the following issues:

  • Cutting speed
  • Edge cleanliness
  • Degree of tolerance required
  • Number and types of metal to be cut
  • Capital investment
  • Operating costs
  • Size of heat affected zone
  • Access to secondary machining processes

There is no one overall answer to the question “Which metal cutting system is best?" The factors that are important to one metal processor will be different from those of another depending on their customers’ needs. The “best" metal cutting process depends on the material to be cut and the final application of the material. No one cutting system is superior to another in all major comparison categories.

If you would like more information about our laser cutting services, please use our contact form or email us at info@teskolaser.com.

Tesko Laser Division.
contact Tesko laser division Tesko laser division site map laser cutting and laser safety links laser tips laser cutting and laser safety glossary frequently asked questions benefits laser cutting services About Tesko laser division Tesko laser division home page