Tubular Latch Size Guide

Choosing the correct tubular latch size is an important step when fitting new door handles or replacing an existing latch. While tubular latches are simple mechanisms, they are available in several different sizes, and selecting the wrong one can affect how the door operates and where the handle sits on the door.

This guide explains how tubular latch sizes work, the measurements that matter, and how to choose the right size for your door. Whether you are installing new door furniture or replacing an old latch, understanding these measurements will help ensure a smooth installation.

If you want to explore all available options while reading, you can browse the full range of tubular latches.

What Is a Tubular Latch?

A tubular latch is a spring-loaded mechanism installed inside the edge of a door. It works with door handles or door knobs to keep the door closed. When the handle or knob is turned, the latch retracts into the door, allowing the door to open. When the handle is released, the internal spring pushes the latch bolt back out to hold the door shut.

Tubular latches are most commonly used on internal doors and are compatible with a wide variety of door handles and knobs.

Understanding Tubular Latch Sizes

Tubular latch sizes are typically described using the overall latch length, sometimes referred to as the case length. This measurement refers to the distance from the front faceplate to the end of the latch body.

Another important measurement is the backset, which determines where the door handle or knob sits in relation to the edge of the door.

Case Length

The case length is the most commonly referenced measurement when selecting a tubular latch. This measurement tells you how long the latch body is and how deep the hole in the door needs to be.

Backset

The backset is the distance from the edge of the door to the centre of the spindle hole where the handle connects. A longer backset positions the handle further away from the door edge, which can improve both comfort and appearance.

Common Tubular Latch Sizes

Most internal doors in the UK use one of a few standard latch sizes. These sizes are typically listed in millimetres, although some manufacturers still reference them in inches.

64mm Tubular Latches (2.5 Inch)

A 64mm latch is one of the most commonly used sizes for internal doors fitted with lever handles.

Key features include:

• Approximately 44–45mm backset
• Suitable for many standard internal doors
• Commonly used with lever-on-backplate handles

You can browse available options here: 64mm tubular latches

Because of its shorter backset, this latch places the handle closer to the edge of the door.

76mm Tubular Latches (3 Inch)

The 76mm latch is another very popular size and is often recommended when installing lever-on-rose door handles.

Advantages include:

• Larger backset (typically around 55–57mm)
• Allows the handle to sit further from the door edge
• Often creates a more balanced handle position

View available options here: 76mm tubular latches

90mm Tubular Latches

A 90mm tubular latch provides an even larger backset and is often used when installing door knobs.

Because knobs require more clearance for your hand, the larger backset helps ensure comfortable operation.

Browse the range here: 90mm tubular latches

Larger Tubular Latch Sizes

In addition to the common sizes above, tubular latches are also available in larger sizes, particularly for doors fitted with traditional door knobs or decorative door furniture.

Some tubular latches are available in sizes such as:

• 100mm
• 127mm (often referred to as 5 inch)

These larger sizes provide an extended backset that positions the door knob further away from the door edge.

You can view all available sizes in the main tubular latch collection.

How to Choose the Right Tubular Latch Size

When selecting a tubular latch, consider the following:

• First, measure the existing latch if you are replacing one. Matching the original size usually makes installation much easier.
• Second, consider the type of door furniture you are installing. Lever handles typically work well with 64mm or 76mm latches, while door knobs often benefit from a larger backset such as 90mm.
• Finally, think about how frequently the door will be used. High-traffic doors or heavier handles may benefit from a heavy duty latch for improved durability.

Final Thoughts

Tubular latch sizes may seem confusing at first, but once you understand the key measurements they become much easier to choose.

Most internal doors use either a 64mm or 76mm latch, while larger sizes such as 90mm or 127mm are often used with door knobs or when a larger backset is required.

By measuring carefully and choosing the correct size, you can ensure your door handles operate smoothly and your door closes properly.

To explore all available sizes and styles, browse the complete tubular latch collection.