Drilling for screws is essential for a tight, strong, and more durable wood connection. Wood is needed to connect with one another for many reasons. When you drill for screws, follow the below method for a successful wood connection.
Screws are with different shanks, threads, and heads. These can screw into the wood with pilot holes or directly driven inside. This depends on the strength of the screw, wood, and driving power. The following steps guide you to make a perfect wood connection with screws.
Step 01 – Identify the Wood Type
This is the most important step. When you drive into the wood, you should consider the type of wood. There are types of wood mostly we can categorize them as softwood and hardwood. The hardness is different from each other and used for the specified task. When wood is old, dry, and cured, it is tougher and stronger. This kind of wood is tough to drive or drill.
You can drill hardwood using black oxide drill bits.
So you should choose a strong drill bit for drilling the hardwood for screws. Most screws are too resistant to drive these types of woods. You will need high torque. The screw head can be broken if the torque is increased too much.
There is no problem with softwood. But it can be cracked when you drill or drive the edges. So use a proper way to drive the screw in such places.
- Soft Woods – pine, fir, spruce, larch and cedar, juniper, pine, redwood and spruce
- Hard Woods – alder, balsa, beech, hickory, mahogany, maple, oak, teak, and walnut
Step 02 – Select the Suitable Drill Bit
Driving screw into wood can be done as 02 methods
01. Directly drive using the screw
02. Drive using the pilot hole
When you drive a screw into hardwood the pilot hole is the best way. Softwood can be directly driven with the screw itself. But edge cracking will be a problem. You can choose the right drill bit according to your project. It can be spade bit, twist bit, auger bit, or any. But the screw diameter size is not much that, so use a drill bit below the shank diameter. When you keep the drill bit on the screw, you should see threads and a small part of the diameter.
If you use a more diameter drill bit than its threads, it will not tighten. If you use too much smaller drill bit, it is useless. So select the drill bit as threads can be seen.
The drill bit should be longer than the screw. You will need two drill bits for the drilling process. One is for the pilot hole, and the one is for the clearness hole. Sometimes you need a countersink drill bit also for the perfect process.
| Screw Size | Nearest Fraction | Millimeter |
| #0 | 1/16 | 1.5 |
| #1 | 5/64 | 1.8 |
| #2 | 3/32 | 2.0 |
| #3 | 7/64 | 2.3 |
| #4 | 7/64 | 2.8 |
| #5 | 1/8 | 3.1 |
| #6 | 9/64 | 3.3 |
| #8 | 5/32 | 4.2 |
| #10 | 3/16 | 4.8 |
| #12 | 7/32 | 5.5 |
| #14 | 1/4 | 6.3 |
| Screw Size | Pilot hole size for hardwoods | Pilot hole size for softwood |
| #1 | 3/64″ | 1/32″ |
| #2 | 3/64″ | 3/32″ |
| #3 | 1/16″ | 3/64″ |
| #4 | 1/16″ | 3/64″ |
| #5 | 5/64″ | 1/16″ |
| #6 | 3/32″ | 5/64″ |
| #7 | 3/32″ | 5/64″ |
| #8 | 1/8″ | 3/32″ |
| #9 | 1/8″ | 3/32″ |
| #10 | 1/8″ | 7/64″ |
| #11 | 5/32″ | 9/64″ |
| #12 | 9/64″ | 1/8 |
You should use an equal diameter drill bit for the pilot hole diameter. Download the drill bit sizes here.
Read More About – 13 Types of Drill Bits for Wood: You Should Know!
Step 03 – Choose the Proper Drilling Machine
In this step, we can choose a suitable drill machine. Many types of drills are available in the market. Among them, you should use regular drills. If you use a cordless drill, it is really easy to handle and tool changes. If you use a bench drill, it is tough to handle. The most suitable way is selecting a regular cordless drill for drilling the clearness hole and pilot hole.
And you will need a screwdriver or impact driver to drive the screws inside the holes. Normally screwdriver is limited power, and an impact driver is really powerful to drive screws into wood.
You can use an impact driver to drive the screws without any pilot holes. But workpiece edges can be cracked due to compression. When the screw is moving inside the wood, it can push away the material. When this happens in the edge, the edge side can be cracked easily. So be careful while you drive using the impact driver only using the impact driver.
Some hardwood is too hard due to being old and dry. So drilling and driving are really hard. When you use impact drivers to drive screws, it can be damaged. Mostly screw head is broken due to high torque. As well as nail drives can be slippered with drive bit movement.
Step 04 – Use Recommended RPM for Drilling Wood
Drilling woods can be recommended for high RPM. If you use low RPM, the drilled hole can be uncleared, and the hole surface is not sharp. Due to this, drilling wood is recommended for the high RPM rate.
Do not forget to apply enough thrust. If you apply, more thrust tools can be overheated, and also drill also overheated. You can apply enough thrust as chips come out gently.
| Drill Bit Diameter | Softwood (RPM) | Hardwood (RPM) |
| 1/16 – 3/16 | 3000 | 3000 |
| 1/4 – 3/8 | 3000 | 1500 |
| 7/16 – 5/8 | 1500 | 750 |
| 1 1/16 – 1 | 750 | 500 |
| 1/8 | 1800 | 1200 |
| 1/4 | 1800 | 1000 |
| 3/8 | 1800 | 750 |
| 1/2 | 1800 | 750 |
| 5/8 | 1800 | 500 |
| 3/4 | 1400 | 250 |
| 7/8 | 1200 | 250 |
| 1 | 1000 | 250 |
| 1/4 – 3/8 | 2400 | 700 |
| 1/2 – 5/8 | 2400 | 500 |
| 36954 | 1500 | 500 |
| 1 1/8 – 1 1/4 | 1000 | 250 |
| 1 3/8 – 2 | 500 | 250 |
| 1/4 – 1/2 | 2000 | 1500 |
| 5/8 – 1 | 1750 | 1500 |
| 1 1/8 – 1 1/2 | 1500 | 1000 |
| 1 5/8 – 2 | 1200 | 700 |
Step 05 – Drill the Pilot Hole
In this step, you should drill the pilot hole first. Mark the screw length on the drill bit using the tape and drill the required place using the drill bit. If the drill bit is penetrating to a marked point, pull out the drill bit.
Step 06 – Drill the Clearance Hole
A clearness hole will tighten the wood layers highly. The pilot hole is not recommended because the screw shank will be tight there, and then the wood will not be tight much.
After the clearness hole is drilled, then use a countersink drill bit to drill the top. Then screw head can fit topper wood perfectly. And the surface will not be rough due to the screw head.
Step 07 – Drive the Screws
After You drilled all holes then drive the screw inside. When you drive a screw, you can use a screwdriver or impact driver. The impact driver is the perfect tool for the driving screws. Sometimes screwdrivers are not able to provide the constant torque to drive the screws inside.
If it is still tight, you can apply to use some soap around the screw. So it will drive nicely.
Step 08 – Clean the Area
When you finish the drilling process, you should clean the area by removing dust and debris. And check whether the wood is really fit by pulling out a bit.
