Comparing sheet metal techniques: what to choose?

Every sheet metal product manufacturer comes to a point when production needs expanding or obsolete machines need to be substituted with new ones. Making a decision about which technology to choose to make an investment in, they should first of all clearly see, what kind of parts will be produced, and from what kind of material.

In cases when the manufacturing technique is not the key factor, or it is not known at the moment (many subcontractors face this), many other factors should be considered. Today, both punching presses and different cutting units ( laser, flame, plasma cutting) are popular on the the sheet metal market.

Laser cutting technology is a competitive player, comparing with shearing and punching techniques. It is especially visible when coming to processing very thin materials (up to 6 mm thin). Laser cutting machines are very efficient and profitable, if a manufacturer focuses on producing small batches of complicated shape parts.

Punching presses should better be used for production of large and middle-sized rectangle parts, with some forming elements required. The ability not only to punch holes, but form them is a significant bonus, and it can be the turning point of decision for some companies.

We have compiled several tables listing advantages and disadvantages of machines that use these techniques. Depending on the manufacturer, machine parameters may change or do not be that explicit.

The table data is statistically average and should be considered as recommendation only. 

LASER CUTTING

Advantages

Disadvantages

No tooling required Slow working speed
Simplicity and quick setup Large investment in the beginning
Cutting complicated contours High energy consumption
Minimum material waste
Narrow cutting
Cutting path optimization
Cutting hard-to-cut sheets
Small micro-wrinkles
Low noise
No deformation

PUNCHING

Advantages

Disadvantages

High productivity and low price Large tooling expenses
Efficient for large and middle-sized part batches Tooling wear-off
Smaller investment in the beginning Long setup time
Forming functions Higher level of noise

You can cut sheet metal using different kinds of matters – a laser beam, oxygen (flame) or plasma.

Laser cutting gains its popularity thanks to a minimum deformation of sheet, ability to achive minimum cut width and a higher level of accuracy. Also, laser-cut parts are well-suited for automatic welding due to accuracy of size. Please see a comparison table of different kinds of cutting below.

The table data is statistically average and should be considered as recommendation only. 

Cutting type

Oxygene (flame)

Plasma

Laser 2,5 kWt

Laser 6 kWt

Energy source oxidizing plasma light light
Energy consumption low average high high
Sheet metal Steel Steel, stainless, aluminum Steel, stainless, aluminum Steel, stainless, aluminum
Steel cutting speed (mm/min) low (500) high(2700) average(1400) average(2100)
Cut width (mm) of 12 mm thick steel average (1,5) large (3,0) small (0,5) small (0,8)
Size accuracy, mm from 1,0 to 2,0 from 0,5 to 1,0 0,2 0,2
Straightness error on 30 mm wide strip 1,5 3,0 0,4 0,4
Straightness of cut surface good я poor high high
Surface quality acceptable good acceptable acceptable
Top edge flame-polishing acceptable poor good good
Environment pollution acceptable high low low
Investment at the beginning low average high high
Maintenance costs high high average average

IMA information:

Italian Machinery Association offers both punching machines and machines for different kinds of cutting. You can find more information about them in our equipment catalog, or by contacting us.

If you are looking for other engineering materials, please read:

Why every engineer should learn machining

How to choose a press brake: 7 factors to consider

Ready for a new CNC machine?

  • In some cases, the existing machines boost their productivity when setup with new tooling of some of the most popular styles. Please go here to see what Italian Machinery Association can offer.
  • You also might need some repair, installation, re-launch or training services for your existing machines. IMA‘s maintenance team has enough skills and experience to solve any problem you might have.
  • Any other questions or inquiries? Don’t hesitate to contact us via phone/e-mail or visit us in any of our offices.