Types of Security Gate Locks: Which Is Best?

It’s 10pm and the dogs start barking. You walk to the front door, look out at the security gate and ask yourself the question every South African homeowner asks at some point: would that lock actually stop someone who was determined to get in? The honest answer depends on which of the many types of security gate locks is holding your gate shut, and how it was fitted.

This guide compares the six main types of security gate locks used in South Africa, explains what makes one lock stronger than another, and helps you decide which one belongs on your gate.

Why the Lock Matters More Than the Gate

A steel security gate is only as strong as the point where it locks, which is why the different types of security gate locks matter so much. Burglars rarely cut through the bars. They attack the lock, the hinges or the fixings, because that is where the gate is weakest.

The risk is real. Stats SA’s Governance, Public Safety and Justice Survey estimates there were about 1.5 million housebreaking incidents in 2024/25, affecting 5.7% of South African households. Housebreaking remains the most common crime South African households experience.

There is also a gap most buyers don’t know about. As MyBroadband reported in 2025, South Africa has no compulsory minimum testing standard for burglar bars, security gates or locks. Two locks that look the same in a shop can perform very differently under attack, so it pays to understand the types of security gate locks before you buy.

What Makes a Security Gate Lock Secure?

Before comparing the types of security gate locks, it helps to know which features actually stop forced entry. Check any lock against these five points:

How it is fixed to the gate. A lock welded into the steel frame has no external bolts or screws to remove. A surface-mounted lock is only as strong as its fixings.
Steel thickness. Thicker mild steel housings resist bending and levering. Look for a stated thickness rather than vague claims like “heavy duty”.
The locking pin. A solid steel pin is harder to cut or snap than a thin latch or a hollow bolt.
A protected mechanism. The parts that do the locking should sit inside the steel housing, where a screwdriver or crowbar can’t reach them.
Fast, reliable locking. In an emergency, you need to lock the gate in seconds, without searching for keys, and it needs to work when the power is off.

Keep these five points in mind as you read through the types of security gate locks below.

The 6 Main Types of Security Gate Locks

1. Weld-in (Weldable) Gate Locks

A weld-in lock is a steel lock body that is welded directly into the frame of a security gate during fabrication. Because the housing becomes part of the gate, there are no fixings on the outside to attack, and the mechanism is enclosed in steel.

Good weld-in locks combine thick casings with solid pins. For example, the Ultra-Small Lock™ Mk2 uses a 12mm solid steel pin in a 2.5mm mild steel casing, and has a keyless emergency locking push pin you can press with one hand.

Best for: steel security gates, burglar gates and steel doors at homes, businesses and estates
Strengths: no external fixings, steel-enclosed mechanism, fast emergency locking, fits flush into the gate
Limitations: needs to be welded in, so it is usually fitted by a gate fabricator or installer

2. Lock Boxes

A lock box is a steel housing welded into the gate that holds a standard lock, such as an Elzette-type lock, a cylinder lock or a 40mm Lince-type deadlock. The box protects the lock body from direct attack and gives the lock a strong, square seat in the gate.

Best for: gates that need a specific brand or type of lock, or matching locks across a property
Strengths: protects an ordinary lock inside welded steel; replacement locks are easy to source
Limitations: only as strong as the lock you put inside it

3. Padlocks

Padlocks are cheap, portable and easy to replace, which is why so many gates still rely on them. The problem is exposure. A padlock hanging on a hasp or chain can be reached from both sides, and bolt cutters, grinders and crowbars all target it easily.

Best for: temporary security or low-risk gates such as garden gates
Strengths: low cost, no installation
Limitations: exposed to cutting and levering; the hasp is often weaker than the padlock

4. Deadlocks and Slam Locks

Deadlocks use a bolt that can only be moved with a key, which makes them more secure than a spring latch. Slam locks lock automatically when the gate closes, which is convenient but means the bolt is spring-loaded. On a security gate, both are usually surface-mounted or fitted into a lock box.

Best for: pedestrian gates and doors where you need keyed access from both sides
Strengths: familiar, widely available, keyed locking
Limitations: surface-mounted versions depend on their fixings; slam locks can be forced more easily than a true deadbolt

5. Electric and Magnetic Locks

Electric strikes and magnetic locks (maglocks) are common on automated gates and in commercial buildings, where they connect to keypads, intercoms and access control. A maglock holds the gate shut with an electromagnet. Most fail open when they lose power, which is a safety feature in a fire but a security risk during load-shedding or an outage.

Best for: access-controlled commercial entrances and automated gates
Strengths: remote and keyless access, access logs
Limitations: depend on power and electronics; need a mechanical backup

6. Smart Locks

Smart locks add Wi-Fi or Bluetooth control, so you can lock or unlock from your phone and see who came in. They are designed mainly for doors, and most are not built to be exposed to rain, dust and direct attack on an outdoor steel gate.

Best for: interior doors and front doors where convenience matters most
Strengths: app control, shared digital keys
Limitations: battery and connectivity dependent; few are designed for outdoor steel gates

Which Type of Security Gate Lock Is Most Secure?

For a steel security gate, the most secure option is a lock that is welded into the frame, built from thick steel, and uses a solid pin with an enclosed mechanism. That rules out most padlocks and surface-mounted locks for high-risk gates, and means electric or smart locks should have a mechanical backup.

Here is how the six types of security gate locks compare on the five points above:

Weld-in locks: welded fixing, thick steel, solid pin, enclosed mechanism, emergency locking. Strongest overall for steel gates.
Lock boxes: welded fixing and enclosed body, but security depends on the lock inside.
Deadlocks and slam locks: keyed and familiar, but often surface-mounted.
Padlocks: cheap and exposed. Best kept for low-risk gates.
Electric and magnetic locks: convenient, but rely on power.
Smart locks: convenient, but rarely built for outdoor steel gates.

The type of gate matters too. A sliding gate needs a lock that can’t be levered sideways, and a double gate needs to lock both leaves together. Our guide on how to choose the right lock for different types of gates covers this in detail.

Why a Better Lock Pays for Itself

A good gate lock costs more upfront than a padlock, but the savings come from three places:

Insurance. Many South African home insurance policies set minimum security requirements. In one case reported by Insurance Chat, a burglary claim was rejected because the home did not have the security gates and burglar bars the policy required. Check your policy wording, and make sure your gates and locks match it.
Fewer replacements. A steel lock that resists weather and wear doesn’t need replacing every few years.
Less loss. The cost of a single break-in, in stolen goods, damage and excess, usually outweighs the price difference between a cheap lock and a good one.

For properties with many gates, a keyed-alike set lets one key open every lock, which saves time and avoids a bunch of different keys. Read more in What Is a Keyed Alike Lock Set?

Frequently Asked Questions

Of all the types of security gate locks, which is best?
For a steel security gate, a weld-in lock with a thick steel housing and a solid steel pin is the strongest choice, because there are no external fixings to remove and the mechanism is protected inside the gate.

Are padlocks safe for security gates?
Padlocks are fine for low-risk gates, but on a main security gate they are exposed to bolt cutters, grinders and levering. A welded lock is more secure.

Do electric gate locks work during load-shedding?
Only if they have battery backup. Many magnetic locks release when the power goes off, so a mechanical lock is a sensible backup on any gate that relies on electric locking.

Can I fit a weld-in lock to an existing gate?
Usually, yes. A gate fabricator or installer can cut the gate frame and weld in a lock or lock box. The exact work depends on the gate’s design.

What is a keyed-alike lock set?
It is a set of locks that all open with the same key. It’s useful for homes, estates and businesses with several gates.

Conclusion

The six main types of security gate locks all have a place, but they don’t offer the same protection. Padlocks and smart locks suit low-risk or indoor use. Deadlocks, slam locks and electric locks work well where convenience and access control matter. For the gate that protects your home or business, a weld-in lock built from thick steel, with a solid pin and an enclosed mechanism, gives the strongest protection at the point where most attacks happen.

Whichever of the types of security gate locks you choose, check the five points in this guide. They’ll tell you more about a lock than its packaging will.

Ready to Secure Your Gate?

Not sure which lock is right for your gate? Ultralock has made weldable security gate locks in South Africa since the late 1980s, for homeowners, businesses and the fabricators who build their gates. Browse the full Ultralock range, from the Ultra-Small Lock™ Mk1 and Mk2 to lock boxes and replacement kits, or contact us and we’ll help you find the right lock for your gate.

6 Types of Security Gate Locks and Which Is Most Secure

Why the Lock Matters More Than the Gate

What Makes a Security Gate Lock Secure?