How to choose a router bit for wood? Here is the definitive handbook that every single artisan should have.

Come scegliere una fresa per legno

Does it ever happen that when you are about to start working you are too busy and you can hardly decide which router bit suits your needs?


Lots of clients call me and even before they say hi they start yelling: I have to do a …, which router bit do I have to use?


Do you want to know what my answer is? I don’t know, I can’t answer you in one second, can we talk a couple of minutes?


“you’re crazy… (they hang up the phone)”


After a while (they always do that) they come to my office and, obviously, they bring me a wrong or broken router bit; in that moment they are willing to talk even more than a couple of minutes and they also give me the chance to dump anything on them, if I wanted to (naturally I never do that; first because I’m honest and second because it’s pointless; if I rip someone off, what to I stand to gain besides loosing clients and bad reviews?)


This is why I have decided to dedicate some time to my blog to at least try to help those who, like my clients, have difficulties every time they start a new production.


I wanted to simplify the process, so I identified 4 fundamental steps:

  • Evaluation of the material
  • Evaluation of the type of making that has to be carried out
  • Evaluation of the type of machine on which the router bit will be used
  • Estimate of the number of pieces that have to be carried out

These are the 4 compulsory key steps that you have to follow when you are choosing your router bit; now we are examining them one by one.



Fist of all you have to know very well the material you are about to mill.

Probably you’re wondering: but isn’t wood all the same? No, it isn’t! Wood is a natural material and there are hundreds of variations; they go from the softest to the hardest one, from the pure to the composite, and I could go on and on and on…

Normally, since spruce and pine are quite pliable, they are the most used.

I chose this as the first step because, the cutter of your router bit will be of a different type of material according to the type of wood you have to work with.

Normally, the cutting parts of the router bit are made of 3 different types of material:

  • Steel (also known as HS – HSS – KS and so on)
  • Hard metal (the famous WIDIA, labelled as HM – HW)
  • Polycrystalline Diamond (PCD – PKD)


The steel cutter can be recognized from the lack of a soldered plate; these router bits weigh much less, if compared to those made of hard metal. As far as the wood field is concerned, with the adoption of hard metal, steel has been completely abandoned but it can be found in router bits for drill (the famous Forstner Bit).

The most important feature is that they can carry out a very precise milling because the metal is less hard than WIDIA, so it can be sharpened with precision

They are used to work pliable wood such as birch and poplar; better if they are pure, which means with no glue residues.

Fresa acciaio

Rputer bits for drill in Steel


Do I recommend this type of cutter? Only for the types of wood nominated above.

Merits and drawbacks? They cost a bit less in comparison to those made of hard metal and, obviously, they last less.



The hard metal or WIDIA (often also written Widiam) is the most used and the most common among all materials. It can be weld-brazed to the router bit or it can be a spare knife.

It is used for any production and all the hobby router bits are made of this material so it is also easily recognizable. It is ideal for pliable and hard wood, with and without residues wood etc… it never fails you.

HW Router bits

Here is a typical cutter made of hard metal, weld-brazed plate

Elical router bit

Helical router bit completely made of hard metal

Do I recommend this type of cutter? Yes, I do, for any type of production.

Merits and drawbacks? Versatility, no evident drawback



As you can understand from its name, the polycrystalline diamond is a very hard material which is perfect for repeated productions and hard materials. Normally it is used on plywood and on chipboard to cut panels through numerically controlled pantographs.

The cutters are small weld-brazed plates which are similar to those in hard metal, except for the colour because these cutters are black. On the contrary, the duration is 40 times superior than the others and, obviously, the prize is higher too. These router bits could be used by the major producers of furniture, such as IKEA.

Helical router bit in polycrystalline diamond (please pay attention to the black welded plate)

Helical router bit in polycrystalline diamond (please pay attention to the black welded plate)


Do I recommend this cutter? Yes, I do, but only to mass-production furniture producers and to those who carry out productions through CNC pantographs.

Merits and drawbacks? They are much more expensive than the other materials but sure enough they are the best for repeated and automatic productions.

Being aware of the type of wood we are going to mill is crucial because once we know it we can choose the right material of our router bit. Probably, those of you who use small DIY router bits won’t fully appreciate what I’m saying and you will be thinking: “what a nonsense…”; I just want you to know that the choice and the study of the material is fundamental for small and medium-sized enterprises because it could determine either the earnings or the loss of an order.


Now that you know how and why you have to know the material that you are about to mill we have to sop a bit longer because we must evaluate the type of making we are about to start.      



Why this evaluation?


Normally people say to me: “Matteo if I have to round I need a router bit that rounds and if I have to make a channel I need a router bit that specifically does it. Haven’t you written this piece just to lengthen the article, have you?”

Don’t worry, now I am going to explain the reason behind all this.

Obviously if you have to round you have to buy a router bit that specifically does it; but I want to draw your attention to these 2 specific questions:

  1. If I have to make a channel, how is the end result supposed to be?
  2. Is it a soft or a massive making? (I’m referring to the part that you are going to removed




When you have to make a channel you have to evaluate both which part of the panel must be machined and how the end result is supposed to be. Why am I telling you this? Because choosing the right cutter not to burn nor to make your material rough is crucial.

There are 4 main types of cutters:


  • STRAIGHT plate cutter
  • POSITIVE propeller cutter
  • NEGATIVE propeller cutter
  • DOUBLE, POSITIVE AND NEGAVITE propeller cutter
This is an example of wood channel

This is an example of wood channel


Each channel has different function. Those of you who downloaded the HANDBOOK will know that for sure; those of you who didn’t have two possibilities: either you download it or you can read THIS ARTICLE where I talk about the choice of the right cutter.


Once you found the right cutter you have to choose the right joint, according to the removal needed. A deeper milling tends to force the router bit in a greater way so, in comparison to soft milling, it needs a bigger support.

Maybe for some of you this is pretty obvious because often are used joints for CNC pantographs (they can reach up to 16-20-25), but for those who still are at a manual level this is a very important choice which is, unfortunately, often, underestimated. An underestimated choice can change both the endurance and the duration of your router bit and, as a consequence, also the success of your production is compromised.



Once you indentified the correct manufacturing along with the right cutter, you found the suitable joint and you analyzed the perfect material to process, you have to ask yourself another question: which machine tool am I going to use?  – the answer might be obvious for you but, in any case, this will help you to think and to decide.


Normally a router bit is used on 2 main machines: the vertical milling cutter (or pantograph)  – which can be both mounted on a bench and held manually – and the CNC numerically controlled milling cutter (or pantograph).


Probably, many of you will be saying that there are more router bits, such as the TOUPIE horizontal milling machine or other little machines such as “lamello” and broaching machines, but I dealt with all this in the previous article which can be read by CLICKING HERE.




In comparison to those who use a numerically controlled milling cutter, I want to state that this point is much more important to those who have a manual milling cutter; nevertheless, I invite you all to read this point because you might find something interesting such as a magic solution to an unfortunate episode that happened to you. So never say never, this part might even ring a bells

Whether you are a DIY enthusiast (very much probable) or you are an artisan who doesn’t want to change the mandrel (I’m joking J), when you use a manual milling cutter the choice of the router bit has a vital importance.

The most important thing you have to take into consideration is the power of the milling cutter.

There are milling cutters of all prizes, you can even find them at 40€, so high and poor quality ones are often considered the same way.

If our milling cutter is low on power and it can’t support joints of 12 or 12.7 mm, we have to be careful because we have to consider if, in the case of hard wood or deep manufacturing, it is worth it to work alone or to pay a visit to a carpenter who can help us. (a hard wood processed with a router bit that has a joint of 6-8mm will easily break, especially if the milling is prolonged).




You can’t expect much from a low-cost milling cutter: you might have a few small millings but sure enough the mechanical part of the tool will be misaligned after a couple of days of work; on the contrary a professional milling cutter (normally it has 2400 w of power) will be extremely reliable, the mechanical part will be perfectly aligned and you will have high quality spare parts.


I can recommend you a very good milling cutter, and I can say that because I tried it out personally: its name is TRITON (2400 w of power). It is very powerful, it is totally reliable and it has always available spare parts. I will use this milling cutter in the videos that I am about to launch.

Manual milling cutter 2400W

This is an example of a vertical manual milling cutter; this the one that I recommend you (2400 w of power)




When you have a numerically controlled milling cutter (or pantograph/CNC milling cutter) the choice will be so much easier.

There is a bigger variety of joints for CNC router bits (in comparison to the manual ones). There are different mandrels for different machine tools (for example ER32 – ER40 – ER20) and there are also different dimensions (for example 8 – 12 – 14 – 15 – 16 – 20 and so on).

When these types of machines are involved it is much more important to stop at point number 2 (soft or massive making) rather than at the evaluation of the machine itself.

CNC pantograph/milling cutter

Here is an example of CNC pantograph/milling cutter, which is numerically controlled.




If you use a manual milling cutter evaluate, very carefully, its power; if you use an automatic pantograph you have to make a very accurate study on the type of milling and you also have to set the working parameters in the proper way (the tool RPM, forward speed and so on… if you want to deepen your knowledge you can find all this in the free HANDBOOK that I wrote).


  1. The manual pantograph that you normally use to trim is an exception; it is a router bit with bearing and it is perfect for the majority of your trims; it doesn’t need a lot of power and it is used to clean the edge and to make it smooth; but if you use a Fraiser router bit you have nothing to worry about!




Esempio di un magazzino di una azienda che produce

Esempio di un magazzino di una azienda che produce “prefabbricati”, ovvero pezzi pronti per essere montati con altri mobili – spesso sono lavorazioni tutte uguali, rivolte a grandi mercatoni o  catene low-cost – quasi sicuramente utilizzeranno frese in diamante.

I will make this quick I promise!

There are 3 main types of materials (a fourth material is coming but it’s too soon to talk to you about this yet J). Undoubtedly Steel HSS – Hard metal and PCD diamond are our best materials; they are able to make your milling smooth, rough or burnt at the right point.

Making a good estimate and repeating predictable calculations could make a huge difference when it comes to profit and loss.



It’s extremely difficult for me to give exact directions about this point; what I can do is give you a comparative estimate of the average tools duration:


  • Steel – we take this as point of reference and we’ll assign it a score of 1
  • Hard metal – we can say that it lasts 4 times longer
  • Diamond – it is 30/40 times more durable than hard metal


An economic alternative is the router bit with an interchangeable knife: you only need spare knives (obviously you can order them when needed). The knife will last much less in comparison to the weld-brazed router bit: the diamond is so much better, end of the story!


Naturally these are general considerations because every single production is different and every single material is “unique”.


The next time you are going to choose a router bit, before buying it, you will take into consideration all these information, because you are able to understand and verify the seller’s proficiency:

  • Evaluation of the material: you have to choose the right material of the cutter so that you won’t have a rough or burnt milling
  • Evaluation of the type of making that has to be carried out: now you are able to choose a strong router bit, along with a compatible cutter; by doing so you won’t have to make up for mistakes that occur while milling.
  • Evaluation of the type of machine on which the router bit will be used: you have to understand if you are able to carry out the production yourself and if you can complete it without loosing the router bit or, worst case scenario, a couple of fingers.
  • Estimate of the number of pieces that have to be carried out: to maximize the profit.


Your milling will be successful – as you probably know if you have read the HANDBOOK to make you milling smooth and without burnings (coming soon)

Today we have leant, or at least I hope so, how to choose the right router bit. Next time I want to see you well-prepared to outclass that clerk that made you feel uncomfortable the last time you guys talked.


I thank you very much for reading this article and also for having wasted 5 minutes of your precious time.


See you next week to discover something new about this wonderful world.




It’s a Fraiser generation!


P.S. If you want to find out the whole range of Fraiser router bits , you are absolutely welcome to visit our online shop; all you have to do is click on the link that you’ve just read or visit the website

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