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How to Choose a Deadbolt: Grade 1 vs Grade 2 vs Grade 3

By Guardian Angel DIY · Updated October 26, 2026 · 11 min read

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A deadbolt is the lock most people trust to protect their home, yet most people have never checked which kind they own. Deadbolts are sold in three quality grades, and the difference between the cheapest and the best can be $20. This guide explains what the grades mean, which features matter, and how to choose the right deadbolt for your door and budget.

Deadbolt vs. the lock in your doorknob

Many doors have two locks. The first is the spring latch in the knob or lever. It is a slanted bolt that springs out to hold the door shut, and a short push or a thin tool such as a credit card can sometimes slip it back. It is a convenience, built to keep the door closed, not to resist attack.

The second is the deadbolt, a solid metal bolt that slides out into the frame and stays there until the key or thumb turn pulls it back. It has no spring and no angle, so it cannot be pushed in. That is why it is called a dead bolt. If a door has only a knob lock, it is not secure. Every exterior door needs a deadbolt, and you need to lock it, since an unlocked deadbolt does nothing.

What Grade 1, 2 and 3 mean

In the United States, residential locks are tested to a standard published by ANSI and BHMA (the American National Standards Institute and the Builders Hardware Manufacturers Association). The test checks how well a lock handles repeated use, how much force it can take, and how it stands up to attack. A lock is then given a grade:

One caution: the grade tells you the lock passed a test, not that it is unbeatable. A Grade 1 deadbolt on a weak door frame will still fail where the frame fails. The grade also covers different things for different parts of the lock, and some products are rated at different grades for different functions. Always read the package, and do not assume. If no grade is printed, treat the lock as ungraded and assume the lowest.

The price gap is small, so we recommend Grade 1 for every exterior door. A Grade 1 lock costs only a few dollars more than a Grade 3 lock, and it is the cheapest security improvement you can buy that you can feel in your hand: the bolt is heavier, the lock turns more smoothly, and the parts are thicker.

Features that matter

Beyond the grade, a few features separate a good deadbolt from a poor one.

• A 1 inch bolt throw. This is how far the bolt extends into the frame. A longer throw gives a deeper grip in the frame. Look for a full 1 inch throw. Shorter bolts are easier to defeat.
• A hardened steel bolt or insert. A saw-resistant hardened insert inside the bolt stops a hacksaw blade from cutting through it.
• Anti-drill protection. Hardened plates and pins protect the cylinder and the lock body from being drilled out.
• Pick and bump resistance. Standard pin cylinders can be opened with picks or a technique called bumping. Many mid-range and premium deadbolts use security pins or other designs that make both harder. This matters most if you worry about a skilled intruder or about a key that others may have copied.
• A solid strike plate and long screws. The strike plate is the metal piece on the frame that the bolt enters. A heavy plate fixed with 3 inch screws reaches the framing behind the jamb. Our guide to reinforcing a front door explains how to do this in ten minutes.
• A solid, smooth feel. It sounds unscientific, but a deadbolt that feels cheap often is. If the thumb turn wobbles in the store, the lock will wobble at home.

Single cylinder vs. double cylinder

A single-cylinder deadbolt uses a key on the outside and a thumb turn on the inside. A double-cylinder deadbolt needs a key on both sides. Double-cylinder locks were designed for doors with glass nearby, so a burglar cannot break the glass, reach in and turn the thumb turn.

The trade-off is serious. In a fire, you need to get out fast, and a double-cylinder lock needs a key at the exact moment you do not have time to look for one. Many places restrict or ban them on residences, and fire officials generally advise against them. For most homes, we recommend a single-cylinder deadbolt. If you have glass within reach of the thumb turn, solve the problem differently: use security film, replace the glass, or move the lock. Check your local codes before installing a double-cylinder lock, and if you do, keep a key in a safe, known place.

Four types of deadbolt compared

Here are four options at different price points. They cover the full range of what most homes need.

1. The basic deadbolt: affordable and better than nothing

A basic, builder-style deadbolt is the cheapest way to add a real bolt to a door that has only a knob lock. It does the job of keeping a door bolted, and it is easy to install. The trade-off is lower strength and durability, and it may not be graded. If you buy one, upgrade the strike plate and the screws at the same time, because that is where it will fail first. It is a reasonable choice for an interior door or a quick fix, but we would not choose it for a front door.

2. The Grade 1 deadbolt: the best value for most doors

A Grade 1 deadbolt from a major lock maker is the pick for most front and back doors. It has a heavy bolt, a hardened construction, and a solid track record. It is not much more expensive than the basic lock, and it is a major upgrade in strength.

3. The pick-resistant deadbolt: extra protection at the cylinder

If you are worried about lock picking or bumping, or many people have held copies of your keys over the years, a deadbolt with a pick-resistant cylinder adds a layer at the keyway. The example below uses a side-locking bar that resists bump keys and picks, and it can be rekeyed in seconds when a key goes missing. The catch is that the grade and the pick resistance are separate things: the base model of this style is rated Grade 3, because the resistance comes from the cylinder design, not from the grade. It is still vulnerable to drilling. That makes it a good choice for a door where key control worries you, and a reason to check the grade on the box before you buy anything marketed as "pick-resistant." If you want both, look for a Grade 1 lock that also lists anti-pick pins, as the Schlage above does.

4. The smart deadbolt: convenience and control

A smart deadbolt replaces the key with a keypad or phone app, and often lets you create codes for family, guests or contractors, check whether the door is locked, and lock it remotely. For many families, the biggest benefit is not needing a key. Think carefully about the trade-offs, though. Smart locks cost several times more than a mechanical lock, depend on batteries, and add software that needs updates. A smart lock is not stronger against a kick than a mechanical one, since the bolt and the frame are the same. Choose one for the convenience and the access control, not as a security upgrade by itself. Look for a model with a mechanical key backup and a Grade 1 or Grade 2 rating.

Installing a deadbolt

Replacing an existing deadbolt is a beginner project. Adding one to a door that has none takes a drill and a hole saw. These points help avoid the common problems:

• Measure the bore. Most residential doors have a 2-1/8 inch hole for the lock body and a smaller 1 inch hole in the edge for the bolt. If your door has them, a standard deadbolt will fit.
• Check the backset. This is the distance from the door edge to the center of the hole. It is usually 2-3/8 inches or 2-3/4 inches. Most deadbolts adjust to either, but check the package.
• Check the door thickness. Standard doors are 1-3/8 to 1-3/4 inches thick. Thicker doors may need an extension kit.
• Use the long screws. Replace the short screws in the strike plate with 3 inch screws.
• Test the alignment. With the door closed, the bolt should slide fully into the strike without rubbing or forcing. If you must lift or push the door to lock it, fix the alignment first, because a lock you cannot easily operate is a lock you will leave open.

Should you change your locks?

Whenever you move into a home, lose a key, or end a relationship where someone had a key, rekey or replace the locks. Rekeying changes the internal pins so the old keys no longer work, and it is often cheaper than buying new locks. Many hardware stores sell rekeying kits for common brands, and a locksmith can do it for a modest fee. Keep track of who has keys, and take back copies when you can.

Which deadbolt should you choose?

Common mistakes to avoid

• Buying by brand or price alone. Read the grade on the package.
• Leaving the short strike plate screws in. It is the most common weak point on a well-locked door.
• Not locking it. A deadbolt only works when the bolt is thrown.
• Using a double-cylinder lock on an exit door without a plan. Safety comes first.
• Hiding a key outside. A key under the mat or in a fake rock is the first place anyone looks.
• Forgetting the other doors. Sliding doors, garage entries and back doors need attention too. See our sliding door guide, and our DIY home security audit for the whole house.

Frequently asked questions