Last updated: August 23, 2021

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Welcome to MONEDEROsmart! If you work with furniture or complex handicrafts in wood, you know how fundamental finishing is. Everything looks better with the screws embedded in the piece, and not exposed, isn't it? That's why you need a reamer!

Reamers, which can also be drill bits, should be used in drilling machines or other similar tools. With them, the hole drilled in the wood becomes enlarged at the tip. But why should you have them? How to choose the best ones? Stay with us to know these answers!


  • Very important for those who work with wood, reamers can eventually help in finishing services in other materials.
  • You can choose between a reamer and a countersink bit. Both options are reliable and offer their advantages, with the decision being a matter of preference.
  • There is no point in having a great reamer, but not knowing how to handle a drill. This tool is also indispensable in the reaming process.

The Best Countersink: Our Picks

Buying guide

You may have many questions about reaming, countersinks, reaming drills and other things we have already mentioned in this article. But don't worry, we have arrived at the buying guide.

We will now answer all the frequently asked questions about this activity and the accessories that allow it to be carried out.

Imagem mostra um homem trabalhando com uma furadeira em madeira.

Joinery work looks much more beautiful with a reamer. (Source: tdjoric /

What is a reamer?

The word reaming does not refer exclusively to actions in wood: According to the dictionary, it refers to the widening of holes for the introduction of nails or screws, or even the action of making the nails and screws stay completely inside a certain object, without the head on the outside.

When we talk about reaming, therefore, we are talking about making a hole that is wider at the tip, so that the screws can also have their head introduced. This is important especially in parts that need a good finish, in craftsmanship or in high-end products.

The act of scarifying is mainly done on wood, but it can also happen on plastics, metals, concrete and other surfaces. To do this, it is only necessary to have the appropriate tools to make the necessary holes safely.

Did you know that reaming can even be done on large surfaces or walls? There are huge machines capable of carrying out this process on an industrial scale. John Wilkinson was the inventor of the reamer in 1775.

In which situations should you ream wood?

When should you ream wood anyway? Why have tools that help you do it accurately and safely?

  • Finishing craftsmanship: Hiding the screws from your craftsmanship is fundamental to the aesthetic beauty of the pieces. So if you use large wood and need to pass through a joint, nothing like reaming: Your work will have much more visual quality!
  • Furniture work: The visual aspect is fundamental when making furniture. Screws in the open get in the way and make the final work unsatisfactory. Whether in industry or in handicraft production, countersinking is always indispensable in this niche.
  • Wooden structures: In huts, floors or structures like domestic bars made with wood, the question is not only aesthetic, since screws sticking out can even hurt people. Reaming is also necessary for quality and safety purposes.

It is worth mentioning that reaming can also be done on similar parts and situations with other materials, although this is not so common.

Reamer or reamer drill?

There are two basic ways of reaming, and they are similar to each other: Through a reamer or a countersink bit. Both require a tool like a drill to be used.

Reamers are small, enlarged pieces that have to be attached to ordinary drills. Usually, the attachment happens with an allen key. They have diameter compatibility limits, but usually already fit a satisfactory range of accessories.

Reamer drills, on the other hand, are already made for reaming, with an enlarged tip. They come in various sizes and diameters and only need to be placed in the drill, just as you would do with ordinary drills.

Your preference should be the main factor in choosing which type to use. Countersink bits are more practical, since it is easier to change them, and they last longer, since the use varies a lot. The price of a kit, on the other hand, is higher than that of a countersink.

We compare the two types in the table below:

Reamers Reamer drills
Form of use Separate piece that must be fixed on simple drills Varied drills that already have the enlarged tip
Advantages Lower price, greater adaptability to varied sizes Easier to change and handle, greater durability
Disadvantages The time to change the piece is longer, suffers with great wear Higher price, it may be difficult to find the ideal drill for the situation

What are the advantages of having good countersink?

When you have good reaming tools, you immediately raise the quality of your work. It doesn't matter what your branch of industry is: More beautiful and well-finished products tend to attract a larger number of customers.

Quality reamers help you to get a perfect finish on your jobs

If you buy quality reamers, you will be able to get the perfect finish on your furniture and crafts. Also, better leveled accessories last longer, are more resistant to constant work and are more versatile, being able to work on surfaces other than wood.

The better finish on your work will allow you to charge higher prices for them and, consequently, earn more money. Reamers are simple, easy-to-use tools that can quickly raise the standard of materials produced by a craftsman or woodworker.

We have prepared a table with the main advantages and disadvantages of having good reamers:

  • It greatly improves the finish and beauty of the pieces
  • It makes for higher prices that can be charged
  • They are durable and resistant
  • The use is quite easy
  • They are accessories of quite specific use
  • They need drills to work

How to use a countersink correctly?

If you choose to buy countersink bits, the use is quite similar to that of ordinary bits in a drill. You must secure them with the chuck (either by key or quick change) and then make use of them. There is not much secret to the process.

The countersink, on the other hand, needs to be attached to the common drill bit. This is usually done with an allen key, which may or may not come with the accessory. Remember that it should be at the tip of the drill bit, and not halfway through, since it is only at the beginning that the hole will be wider.

Specialists recommend that the reaming is done before the hole, that is, it is necessary to measure the screw that will be used, find the correct drill bit and work on this enlarged part. It is also necessary to use high rotation so that the result is appropriate.

Quality drill and screwdriver will also be able to help you a lot in reaming and screwing work.

Purchase criteria: Factors for choosing a countersink

Now that you know you should buy a reamer or reaming drill, it's time to choose the ideal model. We have selected some important criteria to help you:

Below, we'll talk in more detail about each of them!


What are the sizes of the screws you usually use? Are the heads usually wide or thin? Do you know the exact dimensions?

Reamers have minimum and maximum diameter sizes. They indicate in which drill bits they can be installed, representing the dimensions of the holes that will be made. Therefore, you always need to observe the indicated values before finalizing the purchase.

Countersink bits, on the other hand, have varied diameters, just like the normal ones. They come in kits with a high number of pieces. It is important to observe if the required size is contemplated by the chosen set.

Imagem mostra várias brocas escareadoras lado a lado.

Reaming and countersinking burs have varied diameters. (Source: Bru-nO /


A reamer is usually quite small. Reamer drills are larger, but still easy to lose, especially if stored in any way. Any purchase you make should help you safely store such accessories.

A quality case or briefcase even increases the durability of reamers

Always prefer reamers or drills that come with cases, briefcases or pockets that make them easy to carry and store. This not only improves day-to-day practicality by reducing search time, but also increases the durability of each piece.

If you buy a model that doesn't make storage easy, immediately look for somewhere easily accessible to store accessories, preferably without large amounts of other tools along with it.


Setting a countersink drill is very simple, after all, the operation is the same as for a common one. Just press the selected piece in the drill chuck and use it, with no need for adjustment

In the case of the reamer, however, the situation is more complex: Almost always it is necessary to use an allen key, a tool not so common or easy to find. Before turning on the drill, check that the tightening was well done and that the piece is in the right place.

Good reamers also allow you to adjust the depth of the piece in the drill, which is important for those who want to leave the screw perfectly hidden inside the wood.


Whenever we buy items that come in kits, we need to pay attention to cost-effectiveness. This is the case with reamers, but especially with countersink bits.

Remember to divide the total price of the drill kit by the number of units on offer. This way, you'll know exactly how much you're paying for each one, and you'll be able to compare each of the options more effectively.

(Source of the highlighted image: Bru-nO /