Guide · Renting and leases

Duplicate Keys That Work Smoothly

Checking a new copy: what to look at on a new key, how to test it, what to do if a copy is not right, and how to keep locks turning smoothly.

Start the checklist

Where to start

Just got a copy made?
Hold it beside the original and test it with the door open. See compare the copy and test it with the door open.
Have to jiggle a key?
Please don't keep using it. Take it back, with the original. See what to do.
Renting?
Check the lease or ask the owner before copying keys. See ask first in a rental.

The short version

Getting a key copied seems like the easiest errand in the world. Most of the time, the new key works perfectly. Once in a while, though, a copy comes out a little rough or a little off, and you find yourself jiggling it in the lock.

That jiggling can slowly wear out the lock itself. A quick look at a new key before you rely on it saves a lot of frustration later.

Ask first in a rental

Before copying keys to a rental home, please check the lease or ask the owner. Some leases limit copies, and owners usually want to know how many keys are out so they can keep their key log up to date. Some keys are marked "Do Not Duplicate" or are made to be copied only with permission.

Compare the copy to the original

Hold the new key and the original key together, side by side, and look closely.

The shoulders, the small edge near the head of the key, should line up evenly. If they do not, the copy may not work well.
The keys should be the same length.
The cuts should match closely, peak for peak and valley for valley.
Run a fingertip gently along the cuts. If you feel sharp or rough bits, the key may need cleaning up.

Test it with the door open

Always try a new key with the door open, so you cannot get locked out if it does not work.

The key should slide in smoothly without catching.
It should turn the lock easily, without lifting, pulling back or jiggling.
Try it in every lock it is meant for.

If you have to jiggle it, please don't keep using it. Take it back to where it was made and ask them to clean it up or cut a new one, and bring the original with you.

Keeping locks turning smoothly

Oily sprays can strip the grease a lock needs and leave it stickier over time. Some lock makers suggest a dry graphite lubricant made for locks, so check the maker's instructions first.

In a rental, please ask the owner before putting anything into a lock. A lock that has become hard to turn with any key is worth reporting.

Keeping keys safe

A few examples of good habits:

Keep track of every copy and who has it.
Leave a spare with someone you trust, not under a mat, a rock or a planter.
Do not put your address on your key ring.
Tell the owner right away if a key is lost or stolen.

Try it

Your duplicate key checklist

From the guide’s own checklist. Tick each one as you go. These are examples; your home may need others.

0 of 6

Owner asked before copying rental keys
Copy compared side by side with the original
New key tested with the door open, in every lock
No jiggling; rough copies taken back to be fixed
Nothing put into a rental lock without asking
Every copy tracked, and lost keys reported

An everyday example

Three roommates asked the owner if they could each have a key, and the owner said yes and added the copies to the key log. When the new keys came home, one slid in easily but two had to be wiggled to turn. Holding them beside the original, the roommates could see rough edges along the cuts. They took the two keys back, with the original, and had them recut. The new copies turned smoothly on the first try.

Test yourself

How much do you remember?

4 quick questions from this guide, with a one line why for each. Totally optional, no sign in, and your answers are never saved.

From The Perfect Series

Go deeper with The Perfect Move-In Checklist Workbook

Simple, step by step checklists you can write in for moving in: the move in walk, moving day, your first week, utilities, keys and more.

See The Perfect Move-In Checklist Workbook All books in The Perfect Series

Keep this guide handy

Save this page, come back to your checklist any time, and share it with anyone in your home who could use it.

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From the Bunklow shop

Take it with you

Bunklow Home Guide 120: Duplicate Key Cut Testing, Burr Removal, and Cylinder Smoothness ChecksA printable guide to duplicate key cut testing, burr removal, and cylinder smoothness checks, in plain steps.
See it in the shop

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This guide shares general educational information to help you, and is not legal advice or a substitute for a licensed professional. Bunklow does not inspect homes, install locks or make repairs. Lock and key rules differ from state to state and town to town, so please check your state and local law and your lease, follow the maker's instructions, and get local help from a licensed locksmith for lock work.