Slam Lock vs Deadlock on Security Gates

Updated September 2026 by Florin Ristea, General Manager.

A slam lock latches by itself when the gate swings shut, so a door used all day is never left open by mistake. A deadlock is thrown and released with a key, so a barrier locked at night stays locked. Robo Door states the lock type and number of locking points on every quotation; the opening decides which.

The two locks, plainly

	Slam lock	Deadlock
How it locks	Spring latch engages when the leaf closes; key to open	Bolt thrown and withdrawn by key, both sides
Everyday use	Close it and it is locked; no key needed to secure	Locking is a deliberate act with a key
Risk	Locking yourself out; a latch is only as good as its keeper	Forgetting to lock it; needing the key to get out in a hurry
Suits	Kitchen and side doors, pedestrian gates, shop doors, anywhere traffic is constant	Patio sliders and internal barriers locked at night, front doors with a routine
Where it goes	Hinged burglar doors, swing gates, pedestrian gates	Trellis doors, hinged doors, sliding gates

Choose a slam lock when

The door is used constantly and the point is that nobody has to remember to lock it: a kitchen door onto the yard, a side gate the family uses all day, a pedestrian gate beside the driveway, a shop door during trading. The leaf must close square against its keeper every time for the latch to engage, which is why a slam-locked door is fitted with particular care to the frame and hinges, and why a dropped leaf is a service call rather than something to live with.

Choose a deadlock when

The barrier is locked as a deliberate routine and stays locked: a patio trellis at night, a passage door to the bedroom wing, a front door barrier behind the main door. A deadlock cannot be sprung and does not depend on the leaf closing perfectly. It does depend on the key being where everyone can find it, which is the escape-route conversation below.

Both on one door

A hinged burglar door on a busy entrance is often specified with a slam lock for the day and a deadlock for the night, so the door is secured every time it closes and locked hard once the house is in. The quotation lists both, and the second lock is a small line against the cost of the door.

Locking points on wide leaves

A lock is one point of engagement. A wide trellis door or a tall hinged leaf needs more than one, so the leaf cannot be levered at the top or bottom while the lock holds the middle. The number of locking points on a Robo Door product is set by the width and height of the leaf and stated on the quotation; a double-leaf trellis locks where the leaves meet. Comparing two quotations means comparing that number, not only the lock type.

Keys, cylinders and access control

Cylinder locks take a keyed cylinder that can be changed without changing the lock body, which matters when a key is lost or a tenant moves out. Padlock-compatible fittings suit outbuildings and gates that are secured occasionally. Where access control is planned, the gate is prepared for it at the factory so nothing is drilled through the coating later, which would count as a modification under our terms. Ask for keyed-alike cylinders if you want one key for several barriers; it is a specification line, not an afterthought.

Escape routes

Every locked barrier is also an exit. A deadlocked trellis on the patio needs its key on a hook everyone knows, not in a drawer. A slam-locked kitchen door needs the key on the inside within reach. Robo Door's site visit walks the escape routes with you and the lock choice follows from that walk, not the other way round.

Driveway gates

An automated sliding or swing driveway gate is held by the motor and its lock function, with a manual release for power cuts. A separate mechanical lock is specified where the gate must be secured with the motor released, or where the property is left for long periods. The motor carries its own terms; the gate carries Robo Door's two-year manufacturing warranty.

Maintenance

Locks are moving parts. Our terms ask for lubrication of hinges, rollers and moving parts every six months, and a lock that is stiff, sticking or no longer lining up with its keeper is a service call before it becomes a break. Do not oil a cylinder with heavy grease; a light lock lubricant is the right product.

What the quotation states

Lock type on each leaf: slam lock, deadlock or both
Number of locking points
Cylinder type and whether cylinders are keyed alike
Access-control preparation, where planned
Handover of keys and remotes

If a quotation from anyone says only "with lock", ask which lock and how many points. On a Robo Door quotation the answer is already on the page.

Next step

Tell the consultant which doors you use most and they will put the lock type and count on the quote, door by door. Request a free quote, WhatsApp +27 82 888 1919 or call 082 888 1919.