So you just found out about dowel screws and you want to learn more about how to use them and their applications? Then you are in the right place!
Here’s the quick answer. A dowel screw is used for wood-to-wood connection. One of their classic application is for attaching legs to chairs or tables. How to use them? Drill pilot holes for both the screw’s ends; apply some glue for added strength; use the appropriate tool to drive one end into the wood; attach the other piece to it.
Pretty simple, isn’t it? Before diving into these steps deeper, let’s learn more about dowel screws and what are they used for.
What are Dowel Screws?
Dowel screws are headless, tapered fasteners. Both their ends are threaded and pointed so that they can be inserted into the pieces of wood that need to be joined. In the middle of the screw, there’s a small, unthreaded portion, which is usually referred to as a “collar”. This portion is not always present, especially in smaller dowel screws.
Many diameters and length dimensions are available. The most common diameter sizes start at 1/4 inches, up to 1/2 inches. There’s more variety in length, usually starting at 3/4, going up to 4 inches.
Choosing the appropriate size is very important: using a dowel screw that is too big might weaken the surrounding wood since it would require a too large pilot hole. A good rule of thumb here is staying below half the width of the stock. If you are using plywood or softwood, it might be wise to use even smaller dowel screws.
What are Dowel Screws Used For?
Their singular design makes dowel screws perfect for a variety of projects, such as:
- Furniture making. Dowel screws are usually made of stainless steel, which guarantees plenty of strength. That makes them ideal for joining legs to chairs, for example;
- Cabinetry making. Amongst the other things, I think dowel screws are a very quick and handy way to attach handles. The results are always spotless;
- Carpentry projects. What if you want to use dowel screws for outdoor projects? Luckily, dowel screws are galvanized in most cases, so they are resistant to moisture and ideal for outdoor applications;
- Every woodworking application that requires clean-looking joints. Once installed, dowel screws are invisible.
Typically, dowel screws are used to connect the legs to a table or a chair. That’s the kind of project we are going to address in the following paragraph.
How to Use Dowel Screws? A Step by Step Guide
If it’s your first time working with dowel screws, you might be wondering how to use them since they come with no head. Don’t worry, it’s quite straightforward. It all comes down to using the right tool. Make sure you follow the next steps to get the job done properly.
1) Mark and Prepare the Pilot Holes
In order to get the best results, you should pre-drill the holes that will accommodate the dowel screws. Before you start drilling, mark the spots where you are going to drill on the bottom of the tabletop/chair. Mark all the 4 spots. While you are at it, also sign the center of the legs, where the other half of the dowel screw will go.
After that, you can start drilling. Make sure to use a drill bit with a diameter smaller than the dowel screw. If the hole is bigger or has the same dimension as the screw, the latter won’t be able to cling to the wood. Another trick I use to get a stronger joint is drilling not too deep so that the tip of the screw has to latch on wood at the bottom of the hole. Consider using a drill stop or an alternative method to control the depth of your cut.
Make sure that the holes are accurately perpendicular to the contact surface for the best results.
2) Install the Dowel Screw
Now that the holes are ready, you can insert the dowel screw in. For maximum strength, put a bit of glue in before the screw. Starting with the table or chair top, use a dowel screwdriver head to put the screw in. If your dowel screws have an unthreaded collar, drive until the threaded part is completely inserted into the wood. If your dowels are fully threaded, carefully drive half of it in the wood.
What if you don’t have the right screwdriver head? if your dowels are unthreaded in the center, you can use that part to screw the dowel into the piece with a pair of pliers. If your project allows you to do so, insert the screw into one piece with your hands until you can’t, then turn both joining pieces together. The screw will feed itself in.
You could also chuck the dowel screw into the drill directly. Some of the thread will be slightly ruined in the project; you’ll still be able to drive the screw in anyways.
3) Install the Chair/Table Leg
Next, you can install the leg of your table/chair. If you haven’t already, prepare a pilot hole on the contact surface, and add a little glue in it. Make sure to remove all the sawdust before you do that. Finally, drive the leg onto the dowel screw until it tightens up. Let it rest in position until the glue is dried. Then you can enjoy your finished project.
Dowel Screws vs Hanger Bolt: Which one to Choose?
At a first glance, dowel screws and hanger bolt look pretty similar. In reality, they are quite different. And so are their applications.
As we mentioned before, dowel screws come with a lag, wood thread on both sides, for wood to wood applications.
On the other hand, hanger bolts come with a screw end that goes into the wood on one side, and a bolt end on the other. That way, everything that comes with an appropriately size tapped hole can be connected to it. For example, look at the image above: hanger bolts are used to attach pipes to wood studs. In general, they are great for overhead applications. They are also useful if you want to build a knock-down table or if you need to attach metal frames to wood.
In conclusion, dowel screws are ideal for woodworking projects, while hanger bolts are needed when you want to connect something with a threaded insert to wood.
In this quick article, you learned about dowel screws and how to use them. We also talked a little about hanger bolts, a solid alternative to dowel screws when the application requires it.
As you can see, using dowel screws is a quite straightforward process. The key thing is getting the pilot holes right. If they are positioned correctly, and the holes are perfectly perpendicular to the surface that will go in contact, then you have done 90% of the job.