Key Duplication Services

How Key Duplication Actually Works

Most house keys are cut for pin tumbler locks. A duplicating machine clamps your original key next to a blank, traces the cuts with a stylus, and grinds the same pattern into the blank. Two things must be right for the copy to work. First, the blank has to match your lock's keyway, the shaped channel the key slides into. Common residential examples are the KW1 profile used by Kwikset-style locks and the SC1 profile used by Schlage-style locks, and they are not interchangeable. Second, the cut depths, called the bitting, must land within a few thousandths of an inch so each pin stack rises exactly to the shear line. A worn original passes its wear into every copy made from it.

Why Copies of Copies Fail

Every duplication introduces a tiny error. Copy an original and the key usually works fine. Copy that copy, and the errors stack. After two or three generations, the bitting can drift far enough that the pins no longer reach the shear line, and the key binds or refuses to turn.

The fix is cutting to code instead of tracing. Many locks, padlocks, cabinet locks, and vehicle records include a key code that lets a locksmith cut a factory-fresh key to original specifications, with no wear carried over. If your lock, safe, or padlock came with a small code tag, photograph it and store the photo somewhere safe. That number can rebuild your key even if every physical copy is lost.

Keys That Need More Than a Cutting Machine

Some keys cannot be reproduced on a basic tracing machine:

• Transponder car keys contain a chip that must be paired with the vehicle's immobilizer. A perfectly cut blade will turn in the ignition, but the engine will not start until the chip is programmed.
• Laser-cut (sidewinder) keys carry a milled groove down the center of a thick blade and require a milling machine, not a standard duplicator.
• Restricted and high-security keys, including dimple designs, control copying through patent-protected blanks that only authorized dealers can obtain.

A "Do Not Duplicate" stamp on an ordinary key is a request, not real key control. A restricted keyway is what actually prevents unauthorized copies.

When Copying a Key Is the Wrong Fix

Duplication is the right call when you trust everyone who holds a key and simply need more of them. If a key was lost or stolen, more copies do not fix the real problem, which is that an unknown copy may exist. Rekeying the lock so old keys stop working is the safer move. If you carry several different keys for one property, keyed-alike service can set multiple locks to accept a single key. And if a key snapped off inside a lock, do not dig at it with glue or improvised picks, which usually drives the piece deeper; extraction is a job for a locksmith. Not sure which route fits your situation? Call (916) 913-5080, describe your keys and locks, and confirm whether the service can help before anything is scheduled.

Frequently Asked Questions

Can a locksmith make a key without the original?

Often, yes. If the lock or its paperwork includes a key code, a locksmith can cut a new key to factory specifications with no original present. Where no code exists, a locksmith can decode the lock itself or read the bitting from the pieces of a broken key. This is also how a fresh first-generation key gets made when every existing copy is badly worn.

Why does my new copy stick or only work sometimes?

The usual causes are a worn original, a slightly off-spec cut, or the wrong blank profile for your keyway. Because each copy adds a small error, a copy made from another copy is the most common offender. A puff of graphite lubricant can help a marginal key seat, but the durable fix is recutting the key to code or from the cleanest original you have.

Does a Do Not Duplicate stamp legally stop someone from copying my key?

In most cases the stamp is only a request to the person at the counter, and it is widely ignored. If you genuinely need key control, ask about a restricted keyway system. Those use patent-protected blanks that are not sold openly, so copies can only be cut through an authorized channel, often with a signature requirement. That is a mechanical barrier, not an honor system.

Call (916) 913-5080 about key duplication services.