What Hole Saw Size Should I Use for a Door Knob and Deadbolt?

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Many home invasions involve physical force, and believe me, investing in a high-quality door knob and deadbolt lock is among the best ways to ward off these kinds of break-ins.

If you’re thinking of installing one, it’s crucial to know the right hole saw sizes for both the door knob and the deadbolt to ensure your home’s safety. To determine the correct sizing, here’s a guide on hole saw sizes for doorknobs.

Hole Saw Size for Deadbolts and Door Knobs

Drilling holes for doorknobs requires careful planning to ensure success. In the same way, you would want to double-check your measurements before making any cuts while working with wood. You should do the same when dealing with numbers.

#1: Drilling the Doorknob Hole

From my experience in door installations, I can’t stress enough the importance of choosing the correct hole saw size. Always check the doorknob’s packaging first. It’s worth noting that deadbolts and some older lock types often require a primary bore hole size of 2 1/8″.

Check the thickness of your door to ensure that a normal doorknob or deadbolt will fit. In general, a door’s thickness shouldn’t be more than 1-3/8 inches and shouldn’t be less than 1-3/4 inches without serious consideration.

If you want to install a new set of door knobs, you should also measure the backset. The backset is the distance between the door’s edge to the bore hole’s center. 

drilling a doorknob hole

2-3/8 and 2-3/4 inches are the most common sizes available, with the latter being more common for outside doors. Some sets of door knobs contain a latch mechanism that you can adjust to accommodate either backset measurement, making them suitable for use in various situations.

If you don’t have a c-clamp to help guide the hole saw through the door knob, use the template with the lock package to mark the hole’s location. Put the pilot bit of the hole saw you’re using in the exact center of the template.

You should drill through the door until the pilot bit sticks out the other side. Once you’ve drilled halfway through one side, flip it over and repeat the process on the other. Switching sides midway through the cut can avoid blowout and splintering and maintain a neat hole.

#2: Creating a Latch Hole

Precision is key at this stage, as accurate measurements make all the difference.

Having drilled the main hole for the doorknob or lock, your next task is to create a passageway for the sliding bolt.

creating a latch hole

I prefer a 1″ hole saw or spade bit for this task as it works every time. Plus, a 1″ hole saw is often included in your door lock installation kit, so there’s a good chance you already have the right tool on hand.

Related: Hole Saw Size Chart

Although a hole saw might be more precise and a bit slower, it ensures a job well done. Drill perpendicular to the huge diameter hole you just made by marking the drilling site with a clamp template or a piece of paper.

#3: Installing the Faceplate

The faceplate, or edge guard, is the flat metal plate attached to the door’s edge to prevent wear and tear. The faceplate requires a mortise to be cut into the wall using a chisel or router before it can be attached.

Attach the cover plate over the newly drilled hole at the door’s edge. You can draw the perimeter of your mortise by tracing the shape with a pencil.

You can cut the mortise with a hammer and chisel; however, a router will simplify the job.

using chisel to install faceplate

After that, install the faceplate with the screws provided. You can now assemble and install the doorknob or deadbolt through the drilled holes.

After assembling the lock, there’s still a bit of work left before it’s ready for use. You’ll need to mortise the door jamb to fit the strike plate and drill a corresponding hole for the bolt.

#4: Attaching the Strike Plate

The bolt is threaded through a hole in the strike plate, which is a flat metal plate. It is installed directly across from the lock to protect it from being broken [1].

The metal lip on the back of a doorknob strike plate sets it apart from the strike plates used for deadbolts. The door will close more quietly and smoothly with this lip, but you must cut the mortise in a slightly different form than that of a lock strike plate.

A longer, more robust striking plate with additional mounting screw holes is a terrific addition to your lock when it comes to protecting your door from being kicked in.

attaching the strike plate

Installing the strike plate requires aligning the plate’s hole with the deadbolt’s bolt. Simply lengthen the bolt until it depresses into the door jamb, and then cover the flat end with a marker or paint. This neatly outlines the area where a mortise 1/8″ deep should be cut for the strike plate.

Try attaching the striking plate with the provided screws (for maximum safety, use screws that are 2-1/2 inches or longer). The next step is to take out the strike plate and drill a hole for the bolt.

#5: Drilling the Bolt Hole

The last step is to prepare the door jamb for the bolt. Start by drilling a hole in the center of the mortise you just made using a hole saw or spade bit measuring 1 inch in diameter. 

To identify the precise placement of the bolt hole, you can apply the same strategy as before.

Testing the lock is as simple as closing the door after drilling the hole and installing the bolt. When closed, the door and the bolt should glide effortlessly into the door frame.

installing door bolt

You may need a little fine-tuning and rearranging to get the lock working smoothly again.

Conclusion

Every door knob and lock installation necessitates drilling latch holes in the door and fitting a strike plate in the frame.

Recognizing this, I’ve put together a guide detailing the hole saw sizes for door knobs and offering step-by-step instructions on how to correctly install a round door knob handle.

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Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

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