This is the complete guide to drilling wood without splitting. That exists in the whole universe… well, maybe not the entire universe but definitely on the internet.
When you drill wood, you’ve already taken the time to measure it up and marked exactly where you want to drill the hole.
So the last thing you want is to split the wood as you’re drilling because you’ll have to measure it all up again. And you’ll potentially waste an expensive or rare piece of wood.
Therefore, knowing how to do it will save you a bunch of time and frustration, and that’s exactly what I’ll cover in this complete guide.
When I first started woodworking, I would often drill into the wood, and it would begin to split and jam. And I would think to myself, dang! After working alongside a mentor who guided me along the way, I avoided the common mistakes that make the wood split as you’re drilling it.
So, I thought I’d share my experience since I know many beginner woodworkers will run into this issue.
I have been woodworking now for quite a while and am always working on an interesting woodworking project. I have taken a liking to furniture and recently completed a beautiful table.
I’ll quickly give you a summary for how to drill wood without splitting:
To drill wood without splitting, drill you want to carefully choose boards so that where you drill the holes isn’t into or on the edge of a knot, into a prominent grain, and as far away from the wood edges as you can. You also want to drill at the right speed for your drill bit.
I’ll include a reference chart for the right speeds for the different drill bits further down.
This guide is for new woodworkers who have split a piece of wood a few times and want to avoid it. Or for experienced woodworkers who want to make sure they’re aware of everything when it comes to drilling wood.
Whether you’re using a handheld electric drill or a large drill press, I will reveal all in the complete guide.
Where should you place drill holes so that the wood doesn’t split?
When you drill into the wood without assessing the wood’s unique characteristics and exactly where you’re putting the hole, it increases the chance that the wood will split. So, choosing the right boards and the right locations for holes is very important.
Here’s what you need to consider when choosing boards for your project and where not to drill so that you can avoid the chance of your board splitting as you’re drilling into:
- No drilling into knots.
- Not drilling near plains of weakness.
- Not drilling too close to the edge of a board
1. Not drilling into knots
The edges around knots in a board are a lot weaker. Knots will also jam up your drill and require a lot of power and time to get through. If you drill around the edge of a knot, the chances that it will split along the knot outline are very high.
Knots are areas of the wood where a branch has grown. As you may be aware, they are darker in color and usually oval in shape.
When planning out your project or working with recently purchased wood, you want to select boards that don’t have knots. Or boards where the knots won’t be close to where you are drilling.
2. Not drilling near planes of weakness
You can see the grains in the wood. But, some grains are more pronounced than others. The more visible and thicker grains in wood have sap in between them and aren’t as strong as the rest of the board.
There are what are called planes of weakness. It’s an engineering term that means a part of a material such as wood, rock, or concrete that is weak. For example, if a building column has a crack in it.
When you put another story on a building where one of the support beams is already cracked, the extra weight will cause it to break along the crack because it’s already been weakened.
Thick grains in the wood act the same way as a crack in concrete or rock. When you put too much weight on them or drill into them, they will break along the plane of weakness.
When you map out your boards for your woodworking project, you want to look at whether there are any large grains in the board and where they are located. Then plan which boards you’re going to use so that you won’t be drilling into any of them.
When you drill directly into a pronounced grain in the wood, there is a much higher chance that it will split along the pronounced grain as you are drilling the board.
Much like knots in the wood, they are separated by a thin layer of sap, which is more brittle than a piece of board with no knots or pronounced grains.
Also, because the drill is rotating into the wood, it will pull apart the two separate sides of the grain slightly, causing it to split along the board’s length.
Especially when you are drilling into pronounced grain close to the edge of the board. Because the split doesn’t have far to go before it reaches the end of the board, making it split a lot easier.
Also, if a board is already slightly cracked, it’s a lot weaker. And when you begin drilling into it, there’s an excellent chance it will split more. So, avoid drilling into boards that are already slightly cracked.
3. Not drilling too close to the edge of a board
On top of that, you want to avoid drilling close to the edges of a board where you can avoid it. It’s a good idea to plan out where you will drill ahead of time so that where the hole is as far away from the board’s edges as it can be.
Holes that are closer to the edges have a greater chance of splitting because there is no extra support from the rest of the board, strengthening the area around the hole.
When you drill close to the center of a board, the area around the hole is strengthened by the surrounding wood. It’s similar to chopping a thick log with an ax.
If you try to swing your ax right into the center of the log, it’s challenging. And with thick pieces of wood, you can never split it even after you hit it many, many times.
But, if you start by chopping away thin slices from the edges of the log, you will eventually make your way all the way to the center. It requires a lot less energy because the edges are weaker.
It works the same way when you are drilling into wood. When you drill near the edges, they are weaker, so it’s easier to split the wood. Compared to drilling into the center of the wood, which is a lot stronger.
So, marking out your holes and drilling them far from the edges will reduce the chances that your board will wood split when you’re drilling into it.
Drilling a pilot hole stop the wood from the splitting
A pilot hole will make it less likely that the wood will split and drive the screw in straight. This means the screw won’t be sitting flush against the wood, and you’ll have to pull it out or start again. So a pilot hole is always a good idea.
Here’s exactly how to drill a pilot hole:
1. Mark out where you want to drill the pilot hole
2. Plan out how deep and wide the hole should be
1. Mark out where you want to drill the pilot hole
The pilot hole should be exactly where you want to drill the screw. But, consider the places to avoid drilling a hole above – not drilling into or on the edges of knots, as far away from the edges as you can, and not into pronounced grains.
That way, when you’re drilling the pilot hole, it is less likely to split—both when you drill the pilot hole and when you are driving the screw in. Consider using a marking gauge or ruler to be more exact with the hole placement. I have a good post on marking gauges[Link Here]
2. Plan out how deep and wide it should be
For screwing two boards together, you want to drill completely through one board and into the other. There isn’t really a strict rule for this.
But, in my opinion, you want to drill the pilot hole as deep as how tall the screw is. That way, it will prepare the wood for the entire height of the screw, which gives less chance of splitting the wood.
How wide the pilot hole should be is widely accepted to be the width of the screw, not including the teeth. It’s hard to measure because of the way screws are designed. It’s best to eyeball it and err on the side of a smaller drill bit. Because that will give the screw more bite. To hold the screw in place.
You could do it the old fashioned way and just look at the manufacturer specs which will give you the information.
Now you’ve marked out your hole, measured out how deep the hole needs to be, and the right size drill bit, you’ll want to go ahead and drill the pilot hole. But, before you do that, it’s important to know what speed and torque you should use when drilling the hole to lessen the chances that the wood will split, which is the topic of the next section.
Drilling at the right speed for the drillbit to stop the wood from splitting
A common question is whether the speed you use when drilling affects whether the wood will split. Here’s the scoop:
Each drill bit has a speed that works the best to stop the wood from splitting. For example, a flat wood/spade bit needs more speed than a spur wood bit. And also a faster speed. When you drill at a slower speed than it needs, the drill can jam, which makes it more likely the wood will split.
A list of the recommended speeds for all of the different drill bits can be found by clicking here. It’s an excellent PDF document put together but Wood Magazine that you might want to download for your reference.
Do you need to adjust the torque on your drill?
You can adjust the torque on a drill. But, this only comes into play when you’re drilling into stone and metal, according to Drilling-it.com.
For woodworking and carpentry, you only need to adjust the torque based on whether you are drilling or driving in screws. Most handheld drills have different settings for drilling versus driving in screws.
Drills generally make light work of wood. If you put the drill on a higher torque setting, it will use more battery, and you can press harder into the wood to drill holes faster.
But, pressing into the wood with a lot of force isn’t recommended because it will wear out your drill faster. You don’t want to be straining your muscles to push the drill in. You want to let the drill do most of the work and only press into it with enough force to keep the drill moving through the wood.
How do you fix split wood?
You can glue to split together. You want to take a small wedge to prop open the split. And then pour some PVA glue into the top of it. Then allow gravity to spread the glue out. Once that’s done, take a piece of string and use it like tooth floss to spread the glue out.
You can also use a brush to spread the glue out. Then you want to clamp it together and leave it to dry.
If you want to see it in a video, I found this excellent video for how to fix split wood here:
How do you stabilize cracked wood?
You want to use epoxy to fill in the cracks that are the same color as the wood. Epoxy comes in two parts. You need to cut off the amount of epoxy you need to fill the crack and then mash it all together using your hands.
It’s recommended to use gloves to make cleaning up easier and avoid any chemicals from irritating your skin.
You then press it into the split areas using a putty knife or paint scraper. You then scrape off the excess using the putty knife. You then want to leave it to cure. Each epoxy has a different curing time, but you want to sand it down once it’s cured.
Either using a piece of sandpaper or an orbital sander. I recently wrote an article about the [best orbital sander for the money]. You should definitely give it a read because it will save you a lot of time figuring out which one is the best.
If you would like to see a video of someone stabilizing a crack piece of wood then check out the video below:
To drill wood without splitting, you want to choose the right boards and your holes’ location. You want to avoid drilling into and around knots, prominent grains, and close to the edges.
These are weak areas of the wood that make it more likely the wood will split when you drill into it. Also, you want to use the right drill speed for your drill bit. If you use a drill speed that is too slow or too fast for your drill bit, it can make it more likely the wood will split.