Marking, engraving and deep engraving
Laser marking changes the surface without removing much material. On steel this can be annealing, where heat forms a dark oxide layer, or a light etch only a few microns deep. On plastics the laser changes the colour or foams the surface. The mark is permanent but flat, and it is fine for codes and text on finished parts.
Engraving removes material to cut a visible groove. With a fiber laser on metal, this means running many passes, each taking away a thin layer, until the required depth is reached. Engraved marks can be felt with a fingernail and survive wear and light finishing better than a surface mark. Deep engraving takes the same process further, commonly to a few tenths of a millimetre or more, as needed for moulds, dies, tool markings and parts that will be shot blasted or painted. It takes time, because depth grows with the number of passes, and a deep logo can take minutes rather than seconds.
On wood and acrylic, a CO₂ laser engraves by vaporising material in one or a few passes, so depth comes far more easily than on metal.
Fiber for metal, CO₂ for non-metals
For metal, a fiber source is the standard tool. A 30 to 50 W source is commonly chosen where engraving depth matters, because higher power removes more material per pass. Typical jobs include knives, gauges, steel and brass door name plates, ring engraving and tool marking. The fiber laser marking machine page covers source selection in detail.
For non-metals, CO₂ is the usual laser engraving machine. It engraves wood, MDF, bamboo, leather, cast acrylic and rubber, as on wooden plaques and shields and acrylic name plaques. Rubber stamps are also made this way. It also gives a light mark on slate and granite, as on slate photo plaques. Glass can be frosted with CO₂ or marked finely with UV, but neither engraves it deeply. See the CO₂ laser marking machine page for more.
Galvo and flatbed machines
A galvo machine steers the beam with two fast mirrors over a fixed field, commonly around 100 x 100 mm on a standard lens. It is quick and suits repeated marks on parts of similar size. Fiber engravers and most industrial CO₂ markers are galvo machines, and a rotary attachment lets them engrave rings and shafts.
A flatbed machine carries the focusing head on an X-Y gantry over a large table, commonly from around 600 x 400 mm upward, with mirrors guiding the beam from a CO₂ tube along the gantry. It is much slower than a galvo machine for small marks but can engrave large panels in one go and also cut sheet material. That is why house name boards and wooden wedding invitations are usually made on flatbeds. A galvo machine cannot cut through thick sheet, and a flatbed is a slow way to mark a batch of small parts.
Mechanical CNC engraving as an alternative
Not every engraving job needs a laser. A CNC engraving machine cuts the mark with a small rotating cutter and leaves a clean groove with straight walls that can be filled with paint or enamel for contrast. It works on brass, aluminium, steel and engineering plastics and gives true depth without heat discolouration. It has long been the standard method for nameplates and panel labels.
The trade-offs are speed and tool wear. A cutter takes longer than a laser on fine text, and cutters need replacing. For nameplates and precision components where an engraved, paint-filled groove is the specification, CNC engraving is often the better fit. NMB Enterprises offers a CNC Engraving Machine for rotary and flat engraving. Its intended work includes nameplates and precision components, and it also suits tool marking.
What to check before you buy
- Depth. State the depth you need in millimetres. Depth decides the source power and the time per part far more than the size of the logo does.
- Material. Fiber suits metals and CO₂ suits wood and acrylic. A paint-filled groove on a nameplate points to CNC engraving instead.
- Work area. Galvo machines suit parts that fit within about 100 x 100 mm. Panels and full sheets need a flatbed.
- Cycle time. Ask for a timed test engraving at your depth on your material. Deep engraving can take minutes per part.
- Rotary axis. Rings and shafts need a rotary attachment on a galvo machine.
- Extraction. Engraving removes more material than marking, so it produces more fumes and dust. Plan a filtered extractor sized for the job.
- Laser safety. Enclosed cabinets are simplest. Open machines need a controlled area and eyewear rated for the laser wavelength.
NMB's engraving options
NMB Enterprises is an authorised distributor of IndoForeign Technologies laser systems. For metal engraving, the fiber range includes the Compact Fiber Laser Marker and the Desktop Fiber Laser. For non-metals, the UV & CO₂ Specialised Markers apply. The CNC Engraving Machine covers mechanical engraving, and the full range is on the products page.
Laser engraving machine in Tamil Nadu
Demand for a laser engraving machine in Tamil Nadu comes from industry and retail alike. Toolrooms and engineering units in the Ambattur and Guindy industrial estates in Chennai engrave dies and nameplates. Fabrication and component units around Trichy and Coimbatore need deep marks that survive painting.
Kumbakonam is known for brass and bell-metal vessels, which suit engraved names and designs, as on brass lamps and temple bells. Gift shops across Chennai engrave wood and acrylic for corporate mementos and trophies.
Buyers outside Chennai can phone or WhatsApp NMB on 098417 60722 with photos of the part and the depth needed. NMB will suggest a laser engraving machine or the CNC Engraving Machine to suit. NMB is based at Poonamallee, Chennai 600056.