Tool helps you drill perfect lock holes
Q: I have to install a new interior door lockset. The door has no holes in it. How do I drill the holes. Do I just grab my jigsaw?
A: You don’t need special tools to drill the two holes required for the lockset, but it helps if you have a specialized jig, which I’ll describe in a moment.
The last thing you want to use is a jigsaw. You need two different hole saws to create the perfectly round holes in the face of the door and the smaller hole in the edge of the door. The hole diameters are 21⁄
8 inches and 1 inch.
Hole saws have been around for generations. In this tool’s most basic form, think of an empty soup can.
If the metal of the hole saw is thick enough and you can position it at a 90-degree angle to the piece of wood you’re drilling you’ll end up with a clean, perfect hole in the door.
If you want your door lockset to operate smoothly and not bind, it’s imperative that the two holes you drill align perfectly in both directions. The centerline of the holes must be at the same height, and they must be drilled at the precise 90-degree angle to the face of the material being drilled.
To know where to drill this hole from the edge of the door, you need to know the backset of the lockset. The backset is the distance from the edge of the door to the center of the giant hole you drill in the face of the door. Most interior locksets have a 23⁄ 8- inch backset. Exterior locksets commonly have a 23⁄ 4- inch backset.
I disliked interior locksets with the smaller backset as my knuckles always hit the jamb.
You can get in trouble fast if you measure the same backset dimension from the edge of the door. Most doors have a very slight bevel cut that allows the door to not strike the door jamb as it closes. You can see this bevel if you put your square on the face of the hinge side of the door. The hinge side is the side of the door where you see the hinge pins once the door is closed.
The bevel cut can be as much as an eighth of an inch. This means that on the non-hinge side, you would measure an eighth-inch less, so the centerline is the same on both sides of the door and the hole saw pilot bit holes line up. See how easy it is to make a mistake?
With the hole centerline marked out, it’s time to drill. Don’t just drill from one side. You want to drill part way into one side of the door, stop and then start to drill from the other side. This ensures you don’t splinter the wood on the face of the door.
With the large hole cut, it’s now time to drill the small 1-inch hole in the edge of the door. You want to keep the drill level and square.
The lockset jig tool keeps the hole saws square and centered for you. All you have to do is draw the accurate pencil lines so you can align the hole jig.
The best part is that the jig will pay for itself before you finish drilling your first hole.
Tim Carter is a columnist for Tribune Content Agency. He can be reached via his website, www.askthebuilder.com.