How to Install a Deadbolt: The Measurements to Check Before You Drill Anything
Affiliate Disclosure: This article contains affiliate links. If you buy through these links, we may earn a commission at no extra cost to you. Our editorial opinions are our own and are not influenced by affiliate relationships. Read our full disclosure policy →
Contents
Quick Answer
Fitting a deadbolt is a 30-minute job that goes wrong in exactly two places: the measurements you did not take before buying, and the cam position you cannot see once it is assembled. Measure the door first — Schlage specifies a thickness of 1-3/8 in to 1-3/4 in and a backset of 2-3/8 in or 2-3/4 in, and states plainly that outside those ranges the lock will not fit properly. On assembly, the instruction that matters most is that the baseplate cam must be vertical, which Schlage flags twice with a caution. Do not use a power drill to assemble the lock, and test it with the door open so a mistake does not lock you out.
Measure Four Things Before You Buy Anything
Almost every failed deadbolt installation was decided at the checkout, not at the door. Four measurements determine whether a given lock physically fits, and all four take a tape measure and two minutes.
| Measurement | What it should be | What happens if it is not |
|---|
| Door thickness | Between 1-3/8 in and 1-3/4 in | Schlage states the lock will not fit properly outside that range |
| Backset — edge of door to center of the hole | 2-3/8 in or 2-3/4 in | Any other backset and the lock will not fit properly |
| Face hole (cross bore) | 2-1/8 in | Smaller can be enlarged with a 2-1/8 in hole saw. Larger cannot be corrected |
| Edge hole | 1 in | Smaller can be enlarged with a 1 in drill bit. Larger cannot be corrected |
The asymmetry in that last column is the important part. A hole that is too small is a five-minute fix with the right bit; a hole that is already too large cannot be shrunk, and you are into filling and re-drilling or fitting a different lock entirely. Measure before you open the packaging.
Height matters too, though it is more forgiving. Schlage’s installation sheet places the deadbolt 5-1/2 in above the knob or lever on a new installation. On a door with existing holes you are working to what is already there.
The order matters. The cam check in the middle is the step that decides whether the finished lock works at all.For a door that already has holes you need very little: a tape measure, a screwdriver, a pencil and a chisel, plus drill bits in 1/8 in, 7/8 in and 1 in and a 2-1/8 in hole saw if any hole needs enlarging. That is the entire list.
The tool to leave in the box is the one most people reach for. Schlage’s instructions carry the line in capitals: do not use a power drill for installation, and use a screwdriver to remove the product from packaging. The reason is simple — a driver strips the soft screws and over-compresses the assembly, which is a common cause of a lock that binds afterwards. A drill is for making holes in the door, not for assembling the lock.
The Install, Step by Step
This follows Schlage’s own sequence for a keypad deadbolt. A mechanical deadbolt skips the wiring and battery steps and is otherwise identical.
Ten Steps in the Manufacturer’s Order
1
Check the door preparation
Thickness, backset, and both hole sizes against the figures above.
2
Install the bolt
Adjust it to the measured backset. Schlage’s caution: the bolt must remain retracted throughout installation.
3
Rotate the baseplate cam
It must be vertical. Schlage marks this as the step to pay special attention to, warning that a cam in the wrong position stops the lock functioning.
4
Install the keypad
Route the wire over the bolt and slide the tailpiece through its slot.
5
Route the wire and fit the baseplate
The instructions repeat the cam warning here, which is a fair indication of how often it goes wrong.
6
Connect the battery
On the BE365 that is a 9V cell; the lock beeps when it is connected.
7
Tuck the wires and fit the cover
Any routing is acceptable as long as the cover cannot pinch a wire.
8
Install the strike
The hole behind it must be at least 1-1/4 in deep.
9
Test locking
Press the button, rotate the thumbturn toward the door edge, and confirm the bolt extends.
10
Test unlocking
Enter a user code and rotate the thumbturn away from the door edge. If either test fails, remove the lock and check the cam.
The Cam Is the Whole Job
If you remember one thing from this page, make it this. The cam is the small rotating part on the baseplate that the bolt mechanism engages, and it has to be vertical when the baseplate goes on. Schlage flags it as step 3, repeats the warning at step 6, and specifies in the test section that a bolt which will not extend or retract means the lock is not installed correctly and should be removed and reinstalled with close attention to the cam.
The reason it catches people is that everything looks finished. The lock is assembled, the screws are in, the keypad lights up — and the bolt behaves oddly. It is genuinely quicker to take the lock off and start step 3 again than to diagnose it in place. And there is a security dimension as well: a keypad deadbolt whose bolt can be thrown with no code at all is documented as an incorrect installation that leaves the lock insecure, which is one of the symptoms our door lock repair guide covers in detail.
The Strike Plate Is Where Security Actually Lives
The lock resists what the frame lets it resist. Schlage specifies a strike hole at least 1-1/4 in deep, and on a door with existing preparation the instruction is to offer the strike box up to the jamb, trace it, and chisel or drill to correct the preparation if it does not sit properly. A bolt that only engages part of its throw is a bolt doing a fraction of its job.
Two things are worth doing beyond the printed instructions, and both are free. Use the longest screws supplied for the strike, so they reach past the trim into the framing behind it. And check the bolt travels fully into the frame rather than stopping short. Those two details do more for resistance than the difference between rating levels — BHMA’s residential deadbolt standard puts a deadbolt through seventeen security tests including loading the door against it with 1,350 lb of force, and none of that helps if the bolt is sitting in a shallow hole in soft trim. Our guide to what lock grades actually mean covers what those ratings do and do not tell you.
Test It With the Door Open
Schlage puts this in its important notes for a reason: install and test the lock with the door open to avoid being locked out. It sounds obvious and it is skipped constantly, usually by somebody who is confident because the last one went fine.
The Two Tests, and What Failure Means
Locking test
- Press the Schlage button
- Rotate the thumbturn toward the door edge
- The bolt should extend fully
- If it does not, the lock is not installed correctly — check the cam
Unlocking test
- Enter a user code from the label on the instructions
- Rotate the thumbturn away from the door edge
- The bolt should retract fully
- If it does not, remove the lock and reinstall it
Once both tests pass, do one more thing before you put the tools away: change the default codes. They are printed on the instructions and on a sticker behind the keypad, which means they are not secret. Our guide to changing the code on a Schlage lock covers the sequence, and it takes about a minute while the lock is still fresh in your hands.
When to Stop and Call Someone
Three situations. The door is thinner or thicker than the specified range, or the backset is not one of the two standard figures — the lock will not fit properly and forcing it produces a door that neither locks well nor accepts the next lock cleanly. An existing hole is already larger than specification, which cannot be corrected by drilling. Or the door has no preparation at all and you are cutting from scratch, where a misplaced cross bore is permanent.
None of those are beyond a confident DIYer with the right jig, but they are a different job from swapping a lock into existing holes, and they are where the cost of a mistake stops being the price of the lock. If you are choosing hardware rather than fitting it, our Schlage lineup guide and the keyless entry guide cover what fits standard preparation, and our French door guide covers the awkward openings where a standard deadbolt is not the answer at all.
What to Actually Do
Before you buy: measure the door thickness, the backset and both hole sizes, and check them against 1-3/8 in to 1-3/4 in, 2-3/8 in or 2-3/4 in, 2-1/8 in and 1 in. That single step prevents most of the failures in this job, because a hole that is already too large cannot be undone.
During the install: get the cam vertical, keep the bolt retracted, use a screwdriver rather than a power driver, and test both locking and unlocking with the door standing open. Then fit the strike with the longest screws supplied and confirm the bolt travels fully home. What would send this job to a locksmith is a non-standard backset, an oversized existing hole, or a door with no preparation at all — in those cases the lock is not the hard part, the door is.
SafeBode does not yet run an in-house product testing program. This guide is built from manufacturer specifications, official support documentation, current retail listings and verified buyer feedback rather than hands-on testing, and we say so plainly rather than implying testing we have not done.
Frequently Asked Questions
What size hole does a deadbolt need?
The hole through the face of the door should be 2-1/8 inches and the hole in the door edge 1 inch. Smaller holes can be enlarged with a hole saw and a drill bit; holes that are already larger than specification cannot be corrected.
What is a backset and why does it matter?
It is the distance from the edge of the door to the center of the face hole, and it is either 2-3/8 or 2-3/4 inches on standard residential doors. A lock is built for those two figures, so any other measurement means it will not fit properly.
How thick can my door be?
Between 1-3/8 and 1-3/4 inches for a standard residential deadbolt. Outside that range the manufacturer states the lock will not fit properly, which is a fit problem rather than a preference.
Can I use a power drill to install a deadbolt?
Not for the assembly. Schlage’s instructions say plainly not to, and a driver strips soft screws and over-tightens the assembly, which is a common cause of a lock that binds afterwards. Use a drill only for enlarging holes.
Why does my new deadbolt not work after installation?
By far the most common cause is the baseplate cam not being vertical, which the manufacturer flags twice in the instructions. If the bolt will not extend or retract on test, remove the lock and check that step rather than adjusting anything else.
How deep should the strike hole be?
At least 1-1/4 inches, so the bolt can extend fully into the frame. A bolt that only travels part of its length is doing a fraction of the job the lock is rated for.
How long does it take to fit a deadbolt?
About 30 minutes on a door that already has correct preparation, and most of that is measuring and testing rather than assembly. A door with no existing holes is a different job and takes considerably longer.
Should I change the factory codes on a new keypad lock?
Yes, immediately. They are printed both on the instruction sheet and on a sticker behind the keypad, so anyone who has handled the packaging or the lock’s interior has seen them.
Sources
Show sources (3)
