US Locksmith is a licensed (Lic #00443LK) locksmith company serving all of South Florida since 2004. Deadbolts and doorknob locks look similar from the outside, but they work in fundamentally different ways; and the distinction matters for the safety of your home. Understanding which lock type belongs where helps South Florida homeowners build a layered defense against break-ins.
How Does a Deadbolt Lock Differ from a Doorknob Lock?
A deadbolt extends a solid, heavy metal bolt into the door frame when locked. This bolt has no spring mechanism, it can only be moved by turning a key or a thumb turn, which makes it highly resistant to forced entry. A doorknob lock, by contrast, uses a spring-loaded latch that retracts when the knob is turned. The spring latch is convenient for everyday use but can be forced open with a credit card or similar tool because the latch is beveled and not fully seated in the frame.
| Feature | Deadbolt Lock | Doorknob Lock |
|---|---|---|
| Bolt type | Solid, no spring | Spring-loaded latch |
| Forced entry resistance | High | Low to moderate |
| Best location | Exterior doors | Interior doors |
| Can be credit-carded? | No | Yes (beveled latch) |
| Typical cost (installed) | $75–$200 | $40–$120 |
Where Should You Use a Deadbolt vs a Doorknob Lock?
Every exterior door, front door, back door, side door, and garage entry, should have a deadbolt. This is the primary line of defense against forced entry. Interior doors such as bedrooms, bathrooms, and closets typically use doorknob locks because they need privacy rather than heavy security. The strongest setup for an exterior door pairs both: a doorknob lock for everyday convenience plus a deadbolt above it for security.
What Types of Deadbolts Are Available?
Homeowners can choose from three main deadbolt types. A single-cylinder deadbolt has a keyed entry on the outside and a thumb turn on the inside. It is the most common residential choice. A double-cylinder deadbolt requires a key on both sides, which prevents someone from reaching through broken glass to unlock the door but can be a safety concern during emergencies. A smart deadbolt replaces the key with a keypad, fingerprint reader, or app-controlled mechanism while keeping the solid bolt design.
South Florida Tip: Hurricane-Rated Entry Hardware
In South Florida, exterior door hardware may need to meet Miami-Dade County impact standards depending on your location and building code. A licensed locksmith can verify that your deadbolt and strike plate meet local requirements. A weak strike plate can undermine even the best deadbolt.
Can a Locksmith Install or Upgrade Your Deadbolt?
Yes. A licensed locksmith can install a new deadbolt on a door that only has a knob lock, replace an old or worn deadbolt with a higher-security model, reinforce the strike plate with 3-inch screws that reach the door frame studs, and rekey multiple locks to work with a single key. The process typically takes 30 to 60 minutes per door and leaves your entry significantly more secure.
Bottom Line
Deadbolts and doorknob locks serve different purposes. Deadbolts protect, doorknobs provide convenience. And every exterior door in South Florida should have both. If your entry doors rely on doorknob locks alone, upgrading to a deadbolt is one of the most cost-effective security improvements you can make. US Locksmith installs, replaces, and upgrades deadbolts 24/7; call 1-866-776-6062.
Frequently Asked Questions
A deadbolt uses a solid metal bolt with no spring; it can only move when a key or thumb turn is operated. A doorknob lock uses a spring-loaded latch that retracts when the knob turns. Deadbolts are significantly more resistant to forced entry because the bolt cannot be pushed back with a tool or credit card.
Yes, and most security professionals recommend exactly that combination. The doorknob lock provides everyday convenience and a basic latch, while the deadbolt above it adds a solid bolt that resists forced entry. Together they create two layers of security on a single door.
Standard deadbolts can be vulnerable to picking and bump keys. High-security deadbolts from brands like Medeco and Mul-T-Lock use specialized pin designs that resist these techniques. A licensed locksmith can recommend the right security level for your property and budget.
A standard deadbolt installation by US Locksmith in Miami-Dade, Broward, or Palm Beach County typically costs between $75 and $200 depending on the lock grade and whether the door needs to be drilled for a new hole. Call 1-866-776-6062 for a specific quote.
A single-cylinder deadbolt (keyed outside, thumb turn inside) is the most common and safest residential choice because it allows quick exit during emergencies. Double-cylinder deadbolts (keyed both sides) prevent intruders from unlocking the door through broken glass but can trap occupants if a key is not nearby during a fire. Check local building codes before installing a double-cylinder model.
Need Lock Help? Call US Locksmith
US Locksmith is available 24/7 across Miami-Dade, Broward, and Palm Beach County. Licensed (#00443LK), bonded, and insured.
Call 1-866-776-6062Further guidance is published by Miami-Dade County Consumer Protection.