Before you get started on your laser engraving business, it is a good idea to know how deep the engraving can go. This will help you know what type of material you should buy as well as what kind of engraving technique to employ.
So how deep can laser engraving go?
On average, laser engraving can go to a depth of 0.125″ (3.17mm) – 0.020″ (0.51mm). The exact depth of the laser engraving will vary depending on the material used as well as the technique used for engraving. The three commonly used techniques are laser marking, laser etching, and laser engraving. We will look at each of this in greater detail below.
What is laser marking?
Laser marking entails the use of laser beams to make indelible marks on a material. Laser making is also referred to as laser dark marking, laser coloration, charring (for plastics) and annealing (for metals). This technique is commonly used by companies for putting various branding marks on products e.g. best-before-date, brand name, serial numbers, QR codes, logos, UID codes, etc.
Laser making can be achieved in a number of ways:
- Discoloration- a laser beam is irradiated on a surface in order to change its color. A low-powered beam is moved slowly on the material and this beam creates contrast in the color without damaging the material.
- Punching -Works by pressing a numbering head onto the material on which the mark is to be left. Punching works well with metal but it is a very laborious exercise because you will have to change the head for each new mark. It is therefore rarely used.
- Annealing – this is a special method of laser marking that is ideal for making marks on metals. Annealing entails the use of heat from the laser beam to cause oxidation underneath the surface of a metal thereby resulting in a change of color on the metal surface.
- carbon migration – this entails the heating up of the surface with the laser heat and then emitting oxygen and carbon. The result is a darkened surface due to a higher carbon concentration on the marked area.
- staining – staining is achieved when the heat from the laser beam causes a chemical reaction in the material resulting in a change of color. The exact color of the mark made will depend on the chemical composition of the material.
Best materials for laser marking
- Plastics (Polycarbonate, ABS, PMMA, Silicone, Polyester, Polypropylene, Polyimide PI, Poly Ether Ketone, Acrylonitrile Butadiene Styrene Copolymer, and Polyamide).
- Metals (Gold, stainless steel, copper, aluminum, bronze, high-speed steels, carbides, hardened metals, coated metals, anodized aluminum, titanium alloys, titanium, silver, and platinum)
What is laser etching?
Laser etching is the process by which a surface is melted from the heat of a laser beam thereby living a cavity or crevice on the surface. The designs for laser etching can be designed on any computer software that supports vector files. These vector files are then sent to a laser etching machine through a numerically controlled router (CNC). Laser etching usually leaves marks of very shallow depths (approximately 0.001” or less). A typical laser etched mark will be 20 times shallower than the deepest mark that can be made by another engraving technique. Laser etching is suitable for ceramics but it can also be used on some metals and plastics.
Best materials for laser etching
- Metals (anodized aluminum titanium, stainless steel)
What is laser engraving?
Laser engraving is quite similar to laser etching except that it can achieve deeper marks and it doesn’t melt the surface as etching does. Laser engraving uses laser beams to remove material from the surface thereby creating a cavity on the surface. Laser engraving is a very fast process and the removed material is usually completely vaporized by the heat of the laser beam. You can achieve a deeper engraving by allowing the laser beam to pass over the same area several times. The ability to go deeper in the material makes this technique the most ideal of laser marking surfaces that are prone to a lot of wear and tear. A laser engraver can achieve markings of 0.125″ (3.17mm) – 0.020″ (0.51mm).
- Stainless steel
- Carbon fiber
- Carbon nanotube
- Metal plated ceramics
- Inconel metals
Read a more detailed explanation of laser engraving here.
And here is a more comprehensive list of the best materials for laser engraving
The same laser machine can be used for either laser marking, laser etching or laser engraving. However, these three techniques are quite different. The main difference is in how the laser beam from the machine interacts with the material. Understanding these techniques will help you know the best technique to use for different materials.