How to choose engraving bits for mechanical engraving?
The perfect tool for remarkable engravings: our tips for choosing the right engraving cutters
In mechanical engraving, the quality of your engraving projects depends largely on using the right tools. A choice that appears complex given the diversity of materials, cnc engraving machines and applications (engraving, etching or cutting). Let us guide you to learn how to choose the right engraving bits for your needs and your equipment.
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What is an engraving and cutting bit?
Used for engraving and cutting operations on various materials, the milling or engraving cutter is a cutting tool that operates by rapid rotation. This movement allows layers of material to be removed in the form of shavings in order to create slots, profiles, cutouts, or even fine and precise engravings.
The composition of a stylus
The engraving and cutting stylus consists of:
a steel bar (or High Speed Steel, HSS) or carbide cut to useful length;
a flat machined for the requested application;
and a cutting lips, also called teeth.
Two major types of cutter alloys
There are two main types of CNC bits alloy, steel and tungsten carbide.
Steel gives the cutters a certain hardness, and therefore a high resistance to wear and heat. This way they retain their strength and cutting capacity.
When made of Tungsten Carbide, they are known to be extremely strong and durable. These types of CNC bits are particularly used for engraving and cutting the hardest materials.
The Gravotech tip
Tungsten carbide cutters are preferred. They are ideal for very hard materials and high precision applications, because they are more durable.
The different shapes of Gravotech's cutters
To meet specific engraving or cutting needs, and to adapt to all projects and materials, the cutting and engraving end mills are available in different shapes.
Conical
They create a V-shaped groove allowing the legible engraving of very small characters, and an aesthetic rendering typical of engraving with edges that rise and widen.
Cylindrical with flat or round end
They create a groove with straight edges, with an engraving background that will follow the shape of the tool, whether cylindrical or flat.
¼ round
They are designed to create conical grooves. Their shape gives them very high resistance to engraving of hard metals up to a hardness of 60HRC. It also allows for sculpting subtle contours while providing good chip clearance.
Spirals and helicals
Dedicated to cutting, their spiral profile promotes chip evacuation in order to improve cutting quality while achieving higher speeds.
Please note this list only includes the majority of engraving cutters compatible with Gravotech machines. All our references can be found in our ecatalog.
The number of lips for cutting
The more teeth or lips a engraving cutter has, the finer and more even the cut will be.
On the other hand, this level of precision impacts the removal of material, which is then longer.
Conversely, the fewer teeth there are, the faster the chip evacuation, with the downside being a less precise finish.
In this configuration the engraving bits are recommended according to the material to be worked and the precision of the project.
1 tooth:
machining of aluminum, PVC, acetates, light alloys, grooving of non-ferrous materials, cutting and contouring on a CNC machine;
2 teeth:
use on soft materials (aluminum, brass, plastic);
3 teeth:
use for roughing work (rapid and large quantity material removal);
4 teeth:
use for finishing and roughing work thanks to deeper flutes which facilitate good chip clearance.
How to select the ideal cutting and engraving bits
While cutters can handle projects of varying sizes, choosing the right tool can vary from one configuration to another.
You will need to consider the following parameters: technique (engraving, cutting or other), material typology or cnc engraving machine model.
Engraving or cutting?
Whether engraving fine details or cutting thicker materials, the function of the engraving bits is determined by its shape.
As such, the choice of cutter will depend, in part, on its application: engraving, cutting, machining or drilling.
| Engraving (engraving cutters) | Cutting and drilling (cutting cutters) | |
| Cutter shapes |
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For which materials?
Not all cutters are suitable for all materials.
You will need to choose a certain type of cnc bits if your project involves engraving and cutting materials such as:
- two-layer plastic;
- acrylic;
- soft metals (aluminum and brass);
- hard metals (stainless steel and steel).
| Plastics Bi-layer | Plastics | Acrylic | Soft Metals | Hard Metals | Glass | |
| Conical | Engraving | Engraving | Engraving | Engraving | - | - |
| Cylindrical with flat or round end | Engraving | Engraving | Engraving | Engraving | - | - |
| ¼ round | - | - | - | Engraving | Engraving | |
| 45° and 15° conical | Cutting | Cutting | Cutting | Cutting | - | - |
| Spiral and helical | Drilling | Drilling | Drilling | Drilling | - | - |
| Diamond | - | - | - | - | - | Engraving |
For which machine?
To choose an engraving end mill suitable for your CNC engraving machine, you must first look at the compatible tool diameters. In fact, each machine only supports a few cutter diameters. Gravotech offers several ranges of engraving cutters for this purpose. Twincut, Onecut, Percut and Diamond, available in different diameters for different uses.
The TwinCut solution (available in 4.36 mm) is the most versatile. The cutters in this range can be used with a single tool holder, they are interchangeable. Made of carbide, they cover all cutting and engraving applications and support all materials, from plastic to metal, including stainless steel and precious metals.
The OneCut range (available in 3.17, 4.36 and 6.35 mm) offers cutters with a steel or carbide tip, compatible with virtually all Gravotech machines.
The Percut range (available in 3, 4 and 6 mm) has been designed to meet productivity and endurance needs.
It offers short tools for applications requiring a high-frequency clamp or spindle.
The Diamond range is divided into the Onecut and Twincut ranges for better compatibility with machines consistent with their uses. Combining delicacy and precision, these cutters are compatible with scratch engraving projects, particularly on metals and glass. Their action consists of rolling back the material rather than removing it, a technique highly appreciated for producing simple, fine markings without chips.
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