Door Knobs With Locks Explained

Author: Carl Benson

Carl is the founder of Suffolk Latch Company, with a background in engineering and over 20 years’ experience in home hardware. He works closely with suppliers and designers alike to develop quality ironmongery that stands the test of time. Read my full bio.

Door Knobs With Locks Explained

Door knobs with locks can be confusing because, in traditional door furniture, the lock is usually not built into the knob itself. The door knob normally operates a separate latch or lock fitted either inside the edge of the door or mounted on the face of the door.

This guide explains the main locking options used with traditional door knobs, including passage latches, bathroom privacy locks, rim locks, mortice sash locks, deadlocks and external door security. If you are still choosing the right type of door knob, start with our main guide: Door Knobs Explained: The Complete Guide.

To browse traditional internal door knobs, visit our Door Knobs Collection.

Table of Contents

Do Door Knobs Have Locks?

Traditional door knobs do not usually contain the lock inside the knob. Instead, the door knob turns a spindle, which operates a separate latch or lock fitted to the door.

This is different from some modern cylindrical locksets, where the knob and locking mechanism are part of one unit. Traditional British door furniture is usually more flexible. You choose the door knob style separately from the latch, bathroom lock, rim lock or mortice lock behind it.

This means the same style of door knob can often be used across different rooms, provided the correct lock or latch is chosen for each door.

Passage Door Knobs: Latch Only

A passage door knob is used on an internal door that does not need to lock. Typical examples include living rooms, dining rooms, hallways and other internal doors where the door simply needs to stay closed.

In this arrangement, the door knob operates a tubular latch or mortice latch. The latch keeps the door closed, while the knob retracts the latch bolt when turned.

Backset is important here. Door knobs need more hand clearance than lever handles because your hand wraps around the knob. As a general guide, a 64mm or 2½ inch backset should usually be treated as the minimum, while 76mm to 102mm, or 3 to 4 inches, often gives a more comfortable position.

If you are replacing lever handles with door knobs, check the existing latch position carefully. The old latch may place the knob too close to the door frame.

Antique Brass Bathroom Sash Lock - 2.5 Inch

Antique Brass Heavy Duty Tubular Latch - 4 Inch

Privacy Locks for Bathrooms and Bedrooms

Bathrooms, WCs and some bedrooms need privacy rather than high security. In most cases, this is best achieved with a bathroom mortice lock and a separate turn and release.

The turn is fitted on the inside of the room and allows the occupant to lock the door. The release is fitted on the outside and can usually be operated with a coin or flat screwdriver in an emergency.

This is safer than using a simple bolt because access can be gained from outside if a young child locks themselves in or someone becomes unwell and cannot unlock the door.

With this arrangement, the door knob still operates the latch. The privacy function is handled by the separate bathroom lock and turn and release below the knob.

Rim Locks: Surface-Mounted Traditional Locks

A rim lock is a surface-mounted lock fitted to the face of the door. It is commonly found in Victorian, Edwardian and cottage-style properties, especially on internal doors.

Rim locks usually contain a spring latch operated by the door knob and a separate deadbolt operated by a key. Because the lock case remains visible, it becomes part of the traditional appearance of the door.

Rim locks need dedicated rim lock door knobs. The knob on the lock side normally sits directly against the rim lock case, while the knob on the opposite side fixes to the timber door with a rose plate.

If your door has a visible surface-mounted lock case, read Rim Lock Door Knobs Explained before ordering replacement knobs.

Bathroom Rim Locks and Snibs

Some traditional bathroom rim locks include an internal snib. The snib allows the door to be secured from the room side without using a key.

This can work well in period properties where a traditional surface-mounted lock is desired. However, it is important to consider emergency access. Many traditional rim bathroom locks do not include an external emergency release.

If young children, elderly occupants or vulnerable users are likely to use the room, a modern bathroom privacy lock with an emergency release may be the safer option.

When using a bathroom rim lock, always check the handing and installation direction so the snib is positioned on the correct side of the door.

Mortice Sash Locks: Latch and Key Lock

A mortice sash lock is fitted into a recess cut into the edge of the door. It contains two separate functions: a spring latch operated by the door knob and a deadbolt operated by a key.

For internal doors such as studies, home offices or store rooms, a 3-lever mortice sash lock may be suitable where light security or privacy is needed.

The door knob does not provide the security on its own. It operates the latch. The key-operated deadbolt inside the mortice sash lock provides the locking function.

When choosing door knobs for a mortice sash lock, check the backset carefully. A deeper backset usually gives better hand clearance and a more balanced position on traditional panelled doors.

Antique Brass Euro Deadlock - 2.5 Inch

Antique Brass Horizontal 3 Lever Sashlock - 6 Inch

Mortice Deadlocks: Key Locking Only

A mortice deadlock is also fitted into the edge of the door, but it contains only a key-operated deadbolt. It does not contain a spring latch and is not operated by a door knob.

This means a mortice deadlock is often used as a separate security lock. For example, on a front door, the door knob may operate a latch for everyday use, while a separate mortice deadlock provides extra security when the door is locked.

If a door needs to latch closed during normal use, a deadlock alone is not enough. It will need a separate latch or a sash lock that includes both latch and deadbolt functions.

Night Latches and Front Doors

A night latch is a surface-mounted lock commonly used on front doors. It normally has a key-operated cylinder on the outside and a small release lever on the inside.

Unlike a traditional rim lock, a night latch automatically engages when the door closes. This is convenient, but it can also lead to accidental lockouts if you leave without your keys.

A night latch is not normally operated by a pair of traditional door knobs in the same way as a rim lock. On many front doors, a centre door knob or pull is used simply to pull the door closed, while the night latch provides the locking function.

Antique Brass Hammered Thumbturn Bathroom Lock

Antique Brass Oval Bathroom Turn & Release

External Door Security

External doors need proper security. A traditional door knob can be used on a front door, but the knob itself should not be treated as the main security device.

Many UK home insurance policies expect entrance doors to be fitted with a suitable certified lock, such as a British Standard 5-lever mortice lock or another approved locking system. Requirements vary, so it is always worth checking your own policy before replacing external door locks.

Material choice also matters on external doors. Solid brass, bronze and stainless steel are generally better suited to exposed locations. Wooden and cast iron door knobs can work on well-sheltered doors, but they usually need more care and are not the best choice for fully exposed or coastal locations.

Related Reading

These supporting guides explain the main door knob and lock choices in more detail:

• Door Knobs Explained: The Complete Guide
• How to Choose Door Knobs
• Rim Lock Door Knobs Explained
• Rim Lock vs Mortice Door Knobs
• What Are Beehive Door Knobs?
• Wooden Door Knobs Explained
• Cast Iron Door Knobs Explained
• Antique Brass Door Knobs Explained
• Choosing Door Knobs for a Victorian House

Conclusion

When people refer to door knobs with locks, they are usually talking about a traditional door knob used with a separate lock or latch. The door knob operates the latch, while the lock provides privacy or security.

The correct choice depends on the door. Passage doors usually need a latch, bathrooms need a privacy lock, period doors may use rim locks, and external doors need suitable security hardware. Once the lock or latch is correct, choosing the door knob style becomes much easier.

To start choosing, browse our Door Knobs Collection.

FAQ

Can you get door knobs with locks?

Yes, although in traditional door furniture the lock is usually separate from the knob. The door knob operates a latch, rim lock, bathroom lock or mortice sash lock fitted to the door.

Are lockable door knobs secure?

The security depends on the lock fitted to the door, not the knob itself. For internal doors, a simple mortice sash lock may be suitable. For external doors, use a lock that meets your property and insurance requirements.

What door knob lock do I need for a bathroom?

For most bathrooms, use a bathroom mortice lock with a separate turn and release. This provides privacy from inside and emergency access from outside.

What is the difference between a privacy lock and a key lock?

A privacy lock is designed for rooms such as bathrooms and can usually be released from outside in an emergency. A key lock is used where security is needed and requires a key to lock or unlock the door.

Can I use a rim lock on a bathroom door?

Yes, traditional bathroom rim locks can be used, especially in period properties. However, check whether emergency access is needed, as many traditional snib-operated rim locks do not include an external release.

Can door knobs be used on front doors?

Yes, door knobs can be used on front doors, but the main security should come from a suitable external lock. The knob may operate a latch or act as a pull, while the certified lock secures the door.