Last Updated on June 11, 2026
The best deadbolt for home security is a Grade 1 deadbolt. Our picks: best overall security, the Schlage B60/B80 (ANSI Grade 1); best budget, the Kwikset 663; and the best hidden, truly unpickable option, a one-sided (half) deadbolt with no keyhole outside. For a primary entry that needs an outside key, use a Grade 1 keyed deadbolt and add door reinforcement. For a door you lock from inside (garage, back door), a one-sided deadbolt cannot be picked, bumped, or drilled.
We install thousands of deadbolts a year. The best deadbolt depends on the door: a main entry needs a keyed Grade 1 lock, while a door you only lock from inside is best protected by a one-sided deadbolt. Here are our pick and why.
Hidden and unpickable one-sided deadbolts
A one-sided deadbolt has a thumb turn inside and nothing on the outside, so there is no keyhole to pick, bump, drill, or twist out. It is the most attack-proof deadbolt you can buy and costs around $30, price on Amazon. The catch: with no outside key it only works on a door you lock from inside. The rest of this guide is the deep dive on why it is so secure.
Best security: Schlage B60/B62 (ANSI Grade 1)
Grade 1 is the strongest residential rating and the Schlage B-series is the standard we install most for security. Pick-, bump-, and drill-resistant in the right configuration, and built to outlast the door. Schlage B-series on Amazon.
Best budget: Kwikset 663
A solid single-cylinder deadbolt for the money, with Kwikset SmartKey so you can rekey it yourself. Good for interior and lower-risk doors. Kwikset 663 on Amazon.
No exterior keyhole to attack
A one-sided deadbolt, also called a half deadbolt, is only visible from inside the home. From the exterior there is no indication a deadbolt is installed. It is keyless from outside, so it cannot be picked, bumped, drilled, or vandalized. The lock installs halfway into the interior side of the door, so the bore does not go all the way through and nothing shows outside.
One-sided vs single-sided deadbolts
Do not confuse these with single-cylinder deadbolts. “Single” refers to one keyed side; a single-cylinder deadbolt still has an outside keyhole and a thumbturn inside. A double-cylinder deadbolt needs a key on both sides. A one-sided (half) deadbolt has no outside cylinder at all. For our full brand roundup including smart locks, see best lock brands.
The security weakness of traditional, keyed deadbolts
Every keyed deadbolt has the same weak spots: the keyhole and the cylinder. Picking and bumping defeat standard pin cylinders (there are YouTube videos for nearly every lock), drilling targets the pins behind the visible keyhole, and a cheap cylinder can be twisted out. A one-sided deadbolt removes all of those because there is nothing on the outside to attack. See our lock bumping explainer.
A one-sided deadbolt is the most secure
With no exposed parts, there is nothing to pick, bump, pry, or drill, and no sign a lock is even there. Pair it with a door reinforcement kit and the door is practically impenetrable. It is also ideal when someone still has your house key (engage it until you rekey) and for child safety, mounted high on the door so a toddler cannot reach it and slip outside.
One sided deadbolts are more affordable than a high-security
High-security deadbolts (Mul-T-Lock, Medeco) use patented keys and hardened, pick- and bump-proof cylinders, and they often run over $300. They are worth it when you need a keyed outside lock that resists attack, see high-security locks. But if you just need an unpickable lock on a door you secure from inside, a one-sided deadbolt under $30 does it for far less.
How to install a one-sided deadbolt
These require a new hole in the door, so they do not just replace an existing lock, and installation takes carpentry skills (drilling the door and prepping the frame for the strike). Professional installation costs about the same as a regular deadbolt install, a service call plus about an hour of labor and the part, far less than a high-security lock. See what locksmiths charge.
The one drawback
A one-sided deadbolt can only be locked from inside, so it cannot go on a door you regularly enter from outside. In Arizona many homes enter through the garage, so it is a non-issue. On an exterior door you use, it still protects you whenever you are home.
If the main door you use to get into and out of your home is an exterior door (non-garage door), your second most secure deadbolt is a high security deadbolt.
