When to Replace Your Deadbolt

Deadbolts last 15 to 25 years with normal residential use. The lock mechanism itself is remarkably simple... a solid metal bolt that slides into the door frame. There's not much to wear out. What does fail is the internal cylinder (where the key goes), the springs that return the thumb turn, and the tailpiece that connects the two sides. ANSI/BHMA grading tells you a lot about expected lifespan. Grade 1 deadbolts (Schlage B60N, for example) are rated to 250,000 cycles and withstand 10 strikes of 75 pounds of force. These are commercial-quality locks used in residential applications and last 20-25+ years. Grade 2 deadbolts (most Kwikset and mid-range Schlage) are rated to 150,000 cycles. For a door opened 10 times a day, that's 41 years of mechanical life. These last 15-20 years before other components give out. Grade 3 deadbolts are builder-grade minimum... the cheapest locks that meet code. They're rated to 100,000 cycles but use thinner materials that wear faster. Expect 10-15 years. Smart deadbolts (August, Yale, Schlage Encode) have electronics that add failure points. The lock mechanism lasts as long as a traditional deadbolt, but the electronics, motors, and battery contacts may fail in 5 to 10 years. Battery life is 6 to 12 months depending on usage. The most common reason to replace a working deadbolt isn't mechanical failure... it's security. Lock technology improves, and older locks are more vulnerable to picking, bumping, and drilling.

Replacing a deadbolt with a same-size unit takes 15 to 30 minutes with a Phillips screwdriver. Remove 2 screws from the interior plate, pull both halves apart, slide the bolt mechanism out, and reverse the process with the new lock. No drilling required if the bore hole and backset match (standard is 2-1/8" bore and 2-3/8" or 2-3/4" backset).

Installing a deadbolt in a door that doesn't have one takes 30 to 60 minutes. You'll need a 2-1/8" hole saw for the face bore and a 1" spade bit for the edge bore. A deadbolt installation kit ($15-$25) includes the template and bits. Measure carefully... the typical height is 6-12 inches above the existing knob.

Smart lock installation takes 15 to 45 minutes depending on the model. Most retrofit over a standard deadbolt bore. August locks are the quickest since they mount over your existing deadbolt interior. Schlage Encode requires a full deadbolt swap but is still straightforward.

The strike plate is the most overlooked part of installation. Use the reinforced strike plate (usually included with Grade 1 locks) and 3-inch screws that reach the structural framing behind the door jamb. The short screws that come with most strike plates only grab the thin jamb wood.