The lifecycle of a lock.

[Marbles]

I've been studying locks for a few months now, and I have friends and family coming to me for recommendations. Does anyone know how long a lock will last before it should be switched out to ensure it's as functional as it needs to be?

My guess is about every 5 years, since that's when damage due to continued use seems to be pretty apparent both on pins and on the key.

Thoughts?

[averagejoe]

There are several factors here:
What is the lock securing? A high security installation, or the garden shed with nothing of value in it? Higher security places should have locks serviced/replaced more often.
The quality of the lock. Is it a dollar store special, a Masterlock or something high quality like Abloy? Some locks can simply have the cylinder replaced. The cheaper the lock the sooner it will need to be replaced. Some mechanism types last longer that others as well.
How often is it used? If it is opened several times a day it will need to be replaced/serviced more than if it is opened once a week.

Im sure there are more things to consider but I had to write this up quickly

[Marbles]

I'm trying to figure this out for a lot of locks, for some reason people expect it to be a general-rule type of thing that works for all locks. I suppose most of the people I'm talking to are referring to the locks on their front doors, and some to cars. Where the house locks are concerned, they're usually very generic, basic-security locks.

[Evan]

I've been studying locks for a few months now, and I have friends and family coming to me for recommendations. Does anyone know how long a lock will last before it should be switched out to ensure it's as functional as it needs to be?

My guess is about every 5 years, since that's when damage due to continued use seems to be pretty apparent both on pins and on the key.

Thoughts?

@Marbles:

It sounds like you need to keep studying locks if the only ones you have been exposed to are the cheapest of the cheap Grade 3 residential lock sets...

Locks can be re-keyed with brand new pins and worn keys can be replaced... That seems like such a boring routine thing to say but that is what most of an institutional locksmith's time is spent doing: re-keying locks, replacing worn/broken/lost keys...

How long will the typical $10 to $20 DIY installed lock last? Depends on many things:

-- How many times it is used every day...
-- Was it installed and adjusted properly by whomever attached it to the door...
-- Is the door itself properly hung in the opening...
-- Are there any adverse/severe environmental conditions which could affect the lock...
-- Is the lock subjected to physical abuse by the people using it or vandalism by others...

After five years a $10 lock is much more likely to be replaced due to appearance issues or cosmetic damage which doesn't effect the actual functioning of the lock -- you get what you pay for...

If you want a good lock which will last a long time in residential use Arrow Grade 2 lock sets will do you just fine and you can find high security cylinders made to fit in those locks as they are commonly used in light to moderate duty commercial applications...

~~ Evan

[Phrop]

I have never had a locking mechanism fail on me. When it comes to door locks the door frame and latching mechanism is what has failed. I do not doubt that heavily used locks and locks in extreme conditions fail regularly. In my opinion normal house door locks of mediocre quality can last for 20 years or more with no problem and there is no reason to replace or repair them until they show serious signs of wear.

As soon as a lock shows obvious signs of wear, it is time to replace it.

[Marbles]

I'm aware you can change pins and keys, my question was more how often changing them is practical. I mostly study more high security locks, but my friends and family aren't ever going to be asking me about those, they want to know more of what's relevant to them.

And I'm figuring the best way to tell is visible wear. One of the locks I was looking at needs work because there's so much wear on the pins and the key that the key doesn't push the pins high enough to work half the time anymore.

[nothumbs]

I had the same Schlage residential lock on my front door for over 20 years. Still working just fine when I sold the house. The front door was baked in the summer, rained on in the winter. No maintenance done to the lock in that time period. The house I'm in now had locks that had been in place for six years before we repinned them when we moved in. I noticed no functional issues with the locks before we serviced them. I'd say it all depends on duty cycle, location, and luck.

[Evan]

I'm aware you can change pins and keys, my question was more how often changing them is practical. I mostly study more high security locks, but my friends and family aren't ever going to be asking me about those, they want to know more of what's relevant to them.

And I'm figuring the best way to tell is visible wear. One of the locks I was looking at needs work because there's so much wear on the pins and the key that the key doesn't push the pins high enough to work half the time anymore.

@Marbles:

Before access control devices became widely used many office buildings had locked doors to which employees had an actual key to be able to open the door and get into an employee entrance... Now most of those places have proximity card readers and electric door strike releases and the keys to the lock cylinder are for emergency access by management, maintenance, security and the fire department... Such doors in the past could have had thousands of people using thousands of keys (even if they were cut to the same bitting) in the lock DAILY...

Cylinders in such service need to be inspected on a regular basis and re-pinned if anything looks worn... So thousands of times a day (faster wear) versus only a few times a day (much slower wear)...

The same thing can be said about keys, master keys generally are used by people who open many doors each day as opposed to the change keys which open only one room door used by the office workers... Inspecting keys for wear on a periodic basis is a good thing to do, if they look visually worn they should be replaced... The best method to check keys for wear is by measuring them with a key gauge...

The material that a key is made from has an effect on how long it will last, you wouldn't want to give a high school janitor a master key cut on a brass blank, it will wear out much faster than one cut on a nickel-silver blank...

~~ Evan