Drive a Screw

Choose the right diameter of screw: thinner screws for small scale work, or fatter screws for heavier or more structural uses. Typical sizes are #6, #8, and #10. Smaller gauge numbers indicate smaller diameters, and larger numbers indicate larger diameters.

Choose the right length. It is best to screw a thinner piece to a thicker one, rather than the reverse. The screw should go all the way through the top piece and about the same distance into the bottom one (or in some cases at least halfway through the bottom one). When screwing ¾” material together, 1-¼” screws are typical.

Choose the head style. For woodworking, flat head screws are most common since they sit flush with the surface of the wood. Other options include bugle, round, oval, pan, and truss. 

Choose the drive style. Phillips is the most common, but slotted, torx, square, hex, and more are also available. 

The pilot bit should match the core of the screw and be smaller than the threads. Look up a chart, or eyeball it by holding the bit next to the screw. The goal is to remove enough material that the screw doesn’t act like a wedge and split the material, but the threads still cut into the surrounding wood for a strong hold. 

The clearance bit should match the outer diameter of the screw, so that it drops in without engaging the threads. Look up a chart, or just eyeball it by holding the bit next to the screw.

Countersink bits have a conical shape to match the flathead screw. 

Make sure the driver matches the screw. The most common option is a Phillips #2.

Install a bit in chuck. Rotate the chuck sleeve counterclockwise to open the jaws enough to accept the bit or driver. Rotate clockwise to close the jaws. You will hear the chuck click when it is fully tightened. Make sure the bit or driver is centered among all three jaws. 

Forward / Reverse. Push in the arrow pointing towards the front of the drill to spin clockwise (drilling holes, driving screws). Push the arrow pointing towards the back of the drill to spin counterclockwise (removing screws). 

Speed. In addition to the variable speed trigger, the drill has two speed settings. 1 is slower and higher torque; 2 is faster and lower torque. Select 2 for drilling holes and 1 for driving screws. 

Torque. Rotate the mode selection collar to the drill bit symbol when drilling. When driving a screw, choose a torque setting suitable for the size of screw and type of material. Use low torque for small screws and soft materials; use high torque for large screws and hard materials. 

Drill a pilot hole through both pieces. If needed, measure how deep to drill and mark the bit with a tape flag to avoid going too far. 

Drill a clearance hole through ONLY the top piece. Measure how deep to drill and mark the bit with a tape flag to avoid going too far.

Countersink. Use the conical bit to ream out enough room to fit the head of the screw. 

Drive the screw. Keep the drill aligned with the screw, run it slowly, and apply as much pressure as you can to avoid stripping the screw. The goal is to seat it fully so that the head is flush or slightly under the surface of the surrounding wood, and the two pieces are cinched tightly together. 

Problem: There’s a gap between the two pieces.

Solution: Back the screw out until the gap closes, then drive the screw back in. Or, drill a larger clearance hole in the top piece. 

Problem: The screw stripped.

Solution: Remove the stripped screw, throw it away, and get a new one. Make sure you are using the correct size and type of driver. Put the drill in low speed mode. Apply lots of pressure to the drill. Stop if you hear it skipping. In some cases, you may need a larger pilot hole. 

Problem: The screw is stripped and won’t back out. 

Solution: Use vice grips to grasp the head of the screw and twist it out.

Problem: The screw won't start biting into the workpiece.

Solution: Make sure the drill is in forward, not reverse. Use the weight of the drill to “punch” the tip of the screw into the wood slightly to help it get started. Or, make a dimple with an awl or drill a pilot hole. 

Problem: The workpiece split.

Solution: Use a larger clearance and/or pilot drill.

*Usually this occurs near the end of solid wood pieces or between the plies of plywood. 

Problem: The screw sticks up above the surface.

Solution: Use a countersink (or countersink deeper) to make enough room for the head of the screw.

Problem: The screw broke.

Solution: Use vise grips to remove the broken screw if possible. Use a larger diameter screw, or drill larger pilot and/or clearance holes. 

Problem: The screw sticks out the back.

Solution: Use a shorter screw. 

Problem: The screw came out crooked.

Solution: Check your layout to make sure the screw is centered on the piece. If possible, arrange the assembly so you can hold the drill vertical rather than horizontal. Ask someone to spot you to help keep the drill plumb.