A Lock Change Is Far Less Invasive Than People Picture
Most people picture a lock change as a door being taken apart. On the commonest door type in South African housing it is nothing of the sort: one retaining screw comes out of the door edge, the old cylinder slides out, the new one slides in, and the handles, the plate and the door itself are never touched. Our residential locksmith technicians do most of that in a couple of minutes.
What takes the time is everything either side of that. Measuring the cylinder correctly, choosing the right length and grade, adjusting the keep so the new lock is not fighting the frame, and testing it closed before anybody leaves. A locksmith for lock rekey visit involves exactly the same care for a different outcome.
This page covers what happens on each door type, why cylinder length is a security question rather than a fitting detail, when a rekey does the same job for less, and how to tell a lock that has been fitted from one that has merely been inserted.
Need locks changed at your address?
Call with a rough door count and what has prompted it. You get a firm figure before dispatch and the work happens at your door.
What Happens on Each Door Type
Three kinds of lock cover almost every residential door, and the job differs on each.
A euro-profile cylinder — the flat, figure-of-eight barrel found in most modern doors, gates and sliders — is the least invasive by a distance. A single screw through the door edge holds it. Remove that, turn the key slightly to align the cam, and the cylinder slides out. The new one goes in the same way. Nothing else on the door is disturbed at all.
A mortise or lever case sits in a pocket cut into the door edge, so the whole case comes out. That is still straightforward, but the replacement has to suit the existing pocket, the existing handle centres and the existing keyhole position. Where it does not, the door gets cut about — which on an older door is the part that actually costs money, as our locksmith for lock replacement page explains.
A multi-point mechanism runs the full height of the door edge and throws several bolts when the handle lifts. Replacing one means matching the backset, the length and the bolt spacing exactly, and it is the door type where a replacement most often turns out to be unnecessary — a dropped door produces the same symptoms and needs an adjustment rather than hardware. Our locksmith for lock repair page covers the test that separates them.
Cylinder Length Is a Security Question
This is the detail that gets estimated rather than measured, and it matters more than the grade printed on the box.
A euro cylinder is measured from the central screw hole outward, and the two halves are frequently different lengths because the door has furniture on one side and not the other. Get it right and the cylinder sits flush inside the handle plate.
Get it too long and it protrudes. A cylinder standing proud of the plate gives something to grip, and gripping is the first move in the commonest forced-entry method used on this door type. A cylinder that is a few millimetres too long converts a decent lock into an easier one.
Get it too short and it binds. The cam does not reach the mechanism cleanly, the key needs more force each time, and the cylinder wears out early. Neither failure is visible from across the room, which is why measuring rather than estimating is most of the job — and why our locksmith for lock installation assessment starts with the door rather than the catalogue.
Change the Lock, or Rekey It?
These reach the same security outcome by different routes, and the cheaper one is right more often than most people assume. Both get quoted so you choose.
| Rekey the existing cylinder | Change the hardware | |
|---|---|---|
| What physically happens | The cylinder comes out, its internals are reconfigured to a new key, and it goes back into the same door. | The cylinder comes out and a different one goes in, measured to the door and tested before the visit ends. |
| Right when | The hardware is sound and the concern is who holds a key — a move, a departed tenant, a lost set, a contractor. | The mechanism is worn past reliability, under-specified for its door, or has been forced at some point. |
| What you get | Every previously issued key stops working. The grade and condition of the lock are unchanged. | Every previously issued key stops working, and you can upgrade the grade while the labour is being paid for. |
| Cost | The lower figure, because you are paying for labour rather than parts. | Higher, and worth it in the three cases above rather than as a default. |
Where the fault is neither — a lock that is simply dry and full of grit, or a door that has dropped — a service or an adjustment is cheaper than both, and it is a genuinely common outcome rather than a token option offered for form's sake.
What Prompts a Lock Change
Six situations that account for most planned lock work, and what each one actually calls for.
You have just moved in
The working key count is genuinely unknown. Where the hardware is sound, reconfiguring reaches the same outcome for considerably less than replacing.
A tenant has moved out
The risk is rarely the outgoing tenant. It is the cleaner, the partner, the housesitter and the agent who held a set during the marketing period.
A set of keys has been lost
A working key to the property exists somewhere. If anything on the ring identified the address, that matters considerably more.
Somebody tried to force the door
A forced cylinder is replaced rather than serviced, because its internals are strained even where the key still turns perfectly.
The same lock keeps failing
Usually a specification fault rather than bad luck. Hardware too light for its door keeps failing however well it is maintained.
Too many separate keys
Five or six keys for one property is a nuisance rather than security. Bringing the set onto one key during a visit costs a fraction of doing it later.
What Happens on the Visit
Five steps. Two of them are measurement and testing, which is where a lock change is either done properly or not.
- Step 1
Every door is checked
Including the ones that were not mentioned on the phone. Better to find the garage side door now than after a price has been agreed.
- Step 2
Change or rekey is decided with you
Both options priced per door. Where the cylinder is sound and the concern is key holders, the cheaper route gets recommended even though it earns us less.
- Step 3
Cylinders are measured, not estimated
From the central screw hole outward, both halves separately. A protruding cylinder is a weakness in itself and a short one binds.
- Step 4
Fitted, with the keep adjusted
The strike is moved until the bolt enters cleanly. A lock that needs a shove with the door closed is fighting the frame from day one.
- Step 5
Tested and handed over
Operated from both sides, open and closed. Every key handed to you, nothing retained and no record of the key kept.
Not sure whether you need a change or a rekey?
Describe the situation on the phone. Both get priced and you choose — the cheaper answer is recommended when it is the right one.
Cylinder Grades, and What Each Actually Buys
You will be offered a choice. Two minutes on the differences is worth having before somebody decides for you at the door.
- Standard cylinder
- Perfectly adequate on an internal or low-risk door. Paying for more grade there buys nothing you will ever use, and saying so costs us the upsell.
- Anti-snap cylinder
- Engineered to break at a designed point under attack, leaving the locking mechanism intact behind it. On an accessible front door that is a meaningful improvement for a modest difference.
- Restricted profile
- A new key can only be issued against your written authorisation, so a set cannot quietly become two sets. Worth it where staff, tenants or contractors hold keys.
- Outdoor-rated hardware
- For gates and anything exposed. Weather and cycle count rather than appearance, and it is the difference between hardware that lasts and hardware that comes back.
- The frame, whichever you choose
- A very good cylinder going into soft or split timber achieves very little. Reinforcing the keep frequently matters more than the grade above it.
How the Visit Works
Operating commitments rather than claims, and every one of them is visible during the job itself.
Every key produced during the visit is handed to you at the end of it. Nothing is retained, nothing is filed, and no record of the key is kept — on one cylinder or on a whole property.
Read the reviews on our Google Business ProfileCount the Openings Before Anything Is Quoted
A lock change quoted on a description over the phone is a quote for whatever the householder happened to name, and that is reliably fewer doors than the property has.
Ask most households how many locks they own and the answer is two or three — the front door and the back door. Walk the property and it is six or seven: add the vehicle gate, the pedestrian gate, a garden gate, the garage side door, the internal door from the garage, a store room, and whatever secures pool equipment or a generator.
The uncounted ones are uncounted precisely because they are not anybody's daily route, which is also why they carry the oldest and cheapest hardware on the property. Nobody has revisited them since they were first secured with whatever was to hand.
The economic consequence is the important part. Discovered one at a time over a year, each is a separate call-out at whatever the rate is that day. Counted once and dealt with together, the same work costs a fraction of that.
Which is why the work is priced per opening rather than as one figure for the house, and why counting is the first part of the visit rather than a separate exercise. See lock replacement for when a change is genuinely the right answer.
Lock Change by Area
The same service, with the local realities that change how a visit actually runs.
Locksmith for lock change in Sandton
The door count that decides most of the quote, and the four doors people forget to include.
locksmith for lock change SandtonLocksmith for lock change in Fourways
Estate handovers, gate hardware, and the credentials that locks alone never cover.
locksmith for lock change FourwaysLocksmith for lock change in Randburg
Discontinued mortise cases and why an original door should not be cut about for a modern replacement.
locksmith for lock change RandburgLocksmith for lock change in Centurion
Multi-point doors and why the alignment gets checked before any hardware is quoted.
locksmith for lock change CenturionLocksmith for lost keys
Reconfiguring the cylinders you already have, which reaches the same outcome for less where the hardware is sound.
locksmith for lock rekeyLocksmith for home lockout
The urgent version, including what to check before anybody is dispatched and how the opening works.
locksmith for home lockoutWalk the property, then call
A rough door count is all it takes for a firm figure. Every new key is handed to you before the visit ends.
When a Lock Change Is the Right Call
A full lock change is the sensible choice when the problem is bigger than a sticky latch or a loose handle. If you have just moved in, replacing door locks gives you control over who can enter and helps you start fresh with new house keys. The same applies after a break-in, a lost set of keys, or any situation where access may have been compromised; in those moments, home security depends on removing uncertainty, not trying to patch it. A residential locksmith Sandton homeowners trust will also recommend replacement when worn or damaged locks keep jamming, turn unevenly, or no longer close securely. Those are not minor annoyances if the lock body, cylinder, or internal parts have failed beyond repair.
In that case, replacing the hardware is usually safer and more cost-effective than repeated repairs. This is also the practical answer when you are dealing with a house lockout and discover the mechanism is already failing, because forcing it can leave the door unusable. If you are comparing a quick fix with a proper change, a 24 hour locksmith can assess whether the lock can still be serviced or whether replacement is the better long-term solution. For homeowners who need a clear, immediate decision after an access risk, the right approach is straightforward: replace the lock, restore control, and make sure the entry point is secure again. In nearby areas, even an emergency locksmith randburg call may lead to the same advice when the hardware itself is no longer reliable.