Pair a deadbolt rated to ANSI/BHMA standards with an easy-to-operate handle, and measure your door before buying.
A loose strike plate defeats a high-grade lock — the deadbolt matters most on an entry door, and the strike that holds it in the frame second. Most buyers fixate on finish and knob style, then find the new lock doesn’t fit the existing bore. Work through lock type, certification, and measurements in that order.
Which Lock Type Belongs On An Exterior Door?
A single-cylinder deadbolt is standard for US residential front doors — keyed outside, thumbturn inside — giving solid security without blocking exit in a fire.
Double-cylinder deadbolts need a key on both sides, creating an emergency-egress hazard; local codes may restrict them in homes.
Entry knobs and levers handle daily opening but should never replace a deadbolt on an exterior door. Levers need less grip strength than knobs — important for arthritis or limited mobility. Handlesets bundle an exterior grip with an interior knob or lever; confirm the package includes a deadbolt and that trim fits both the lock brand and existing bore spacing.
Mortise and interconnected locks belong on doors built for that system. A bored-cylinder replacement won’t fit a mortise preparation, so identify what you have first.
What Do The ANSI/BHMA Ratings Actually Mean?
ANSI/BHMA certification objectively compares look-alike locks.
Residential hardware earns A (Best), B (Better), or C (Good) ratings across those dimensions. Commercial grades use a separate scale from Grade 1 (highest) to Grade 3. Read the label like a nutrition panel — it tells you what the product was tested to do. Style alone says nothing about durability.
How Do You Measure A Door For New Hardware?
Measure before ordering — nominal “standard door” sizing often fails, retail specs conflict, and the manufacturer’s installation sheet wins when data disagrees.
- Measure door thickness with a tape.
- Measure backset — door edge to bore center. Adjustable latches help, but check the stated range.
- Measure bore diameter, edge-bore diameter, and strike dimensions.
- On a handleset, measure the distance between handle and deadbolt holes.
- Check door handing for levers and mortise locks; some models are reversible, others ship handed.
- Inspect the jamb and strike — long screws should reach framing, not just trim.
Once measurements check out, finish is open — and a tested roundup of top-rated front door hardware sets can save legwork on matching trim and bore spacing.
| Hardware Type | Best For | Watch Out For |
|---|---|---|
| Single-cylinder deadbolt | Standard front-door security | Weak strike plate undermines the lock |
| Double-cylinder deadbolt | Doors with glass near the lock | Egress hazard; may be code-restricted |
| Entry lever | Easier grip for limited hand strength | Never a substitute for a deadbolt |
| Knob | Traditional look | Harder to turn with weak hands |
| Handleset | Grip plus interior option in one package | Verify deadbolt included and bore spacing |
| Mortise lock | Doors already cut for that system | Bored-cylinder replacements will not fit |
| Smart lock | Keyless entry and remote access | Thickness, hub, and battery requirements |
What Should You Check Before Buying A Smart Lock?
A smart lock adds convenience only if it fits your door and phones. Verify door thickness, backset, bore dimensions, deadbolt type, and interior clearance — a bulky interior assembly can jam against the frame.
Wireless terms aren’t interchangeable: Wi-Fi, Bluetooth, Matter, and platform compatibility each differ, and remote operation may require a bridge, hub, subscription, or account. Check supported phone operating systems and regional availability on the current product page, since compatibility shifts between versions.
Install fresh batteries, keep the physical key or interior fallback working, and watch low-battery warnings. Never block the interior thumbturn or exit path — that outranks any smart feature.
Rated finishes are tested for performance, not identical color across brands — order matching pieces from one manufacturer if color consistency matters.
Common Questions
Is a Grade 1 lock necessary for a house?
No. Grade 1 is a commercial tier; a residential deadbolt with an A rating under ANSI/BHMA A156.40 is strong for most homes. Spend the difference on a properly anchored strike plate.
Can I replace just the deadbolt and keep my knob?
Often yes, if the deadbolt matches the existing bore and backset and finishes coordinate. Brands differ in trim shape, so mismatches show up close. Measure first and confirm the latch and strike fit the existing preparation.
Do I need a key on the inside for security?
Most safety guidance says no. A thumbturn lets anyone exit fast in a fire; a double-cylinder lock can trap someone hunting for a key. If glass near the lock worries you, a double-cylinder model may help, but check local code and keep a key staged by the door.
Sources
- ANSI. “BHMA Certified Secure Home Label for Door Hardware.” Supports the A/B/C residential ratings and Grade 1–3 commercial scale.
- ANSI Webstore. “BHMA Door Locking Standards.” Lists the A156.39 and A156.40 standards covering locksets and deadbolts.