Choosing a door knob for an internal door involves more than picking a shape you like. The right fit depends on the door’s thickness, the existing mechanism, the style of your home, and the level of use the knob will endure. For UK homeowners, standard spindle sizes and backset measurements must be matched precisely to avoid a wobbly or non-functional handle. This guide covers the most popular types, materials, installation steps, and where to buy, drawing on manufacturer advice and DIY best practice.
Whether you are replacing a worn passage set in a hallway or upgrading a wardrobe with a decorative porcelain knob, understanding the differences in finishes, locking functions, and dimensional standards will save time and money. Below, we break down what you need to know before making a purchase.
What Are the Best Door Knobs for Internal Doors?
Types of Door Knobs at a Glance
| Icon | Feature | Details |
|---|---|---|
| 🌀 | Finish | Brass, chrome, black, porcelain, glass, wood |
| 🔩 | Use | Internal, external, wardrobe, cabinet |
| 📐 | Size | Standard 50–60mm backplate, 30–50mm projection |
| ⚙️ | Install | Mortice or rim, screwfix kits available |
Key Insights
- Brass and porcelain are the most popular finishes for traditional interiors.
- Modern interiors lean towards matte black or satin chrome door knobs.
- Wooden door knobs offer a natural look but may wear faster in high-use areas.
- Screwfix kits often include spindle, screws, and fixing plates for quick replacement.
- Most internal door knobs fit a standard 35–45mm door thickness.
Fast Facts About Door Knobs
| # | Fact |
|---|---|
| 1 | Standard spindle diameter: 8mm (5/16 inch) for most UK door knobs. |
| 2 | Door knob backplate width typically ranges from 50mm to 60mm. |
| 3 | Mortice door knobs require a rectangular pocket in the door; rim knobs mount on the surface. |
| 4 | Replacing a door knob can take as little as 15 minutes with a screwdriver. |
| 5 | Door knobs are less common on external doors due to security concerns; levers are preferred. |
How Do I Replace a Door Knob?
Assess Your Existing Hardware
Before removing anything, measure the backset (distance from door edge to hole centre) — standard UK/EU is 2 3⁄8″ (60mm) or 2 3⁄4″ (70mm). Also check the crossbar (bore hole diameter), which is typically 2 1⁄8″ (54mm). Door thickness is usually 1 3⁄4″ (44mm) but can vary between 1 1⁄4″ and 3″ or more, as noted by video guides from DIY channels.
Tools and Parts Needed
Most replacements only require a screwdriver, a tape measure, and a new door knob set. A standard screwfix set includes two knobs, a spindle, a latch/case, and screws. Ensure the spindle is 8mm thick to match UK latches and locks, as Hiatt Hardware advises.
If your door is thicker than 45mm, you may need an extended spindle. Measure from the outside of one knob rose to the other to confirm the spindle length required.
Step-by-Step Installation
- Remove old knob by unscrewing visible screws or detaching the rose plate.
- Pull out the spindle and old latch/bolt mechanism.
- Insert the new latch and attach the new spindle.
- Place new knobs onto the spindle and secure with set screws.
- Test operation; adjust screw tension if necessary.
This process aligns with advice from Room for Tuesday, which suggests using a clear template for screw hole placement.
What Is the Difference Between a Door Knob and a Door Handle?
Mechanism and Operation
A door knob requires turning to retract the latch, while a lever handle uses downward or upward pressure. Knobs are often used in traditional homes and can be fitted with privacy locks. Lever handles are more common on external doors and in modern interiors due to easier operation.
Why Choose a Knob Over a Lever?
Knobs suit period properties where authenticity matters — brass knobs align with Victorian styles, wooden knobs with Edwardian. They also take up less space on narrow doors. However, for high-traffic areas or users with limited grip, levers may be more practical.
Standard modern doors (1980×760mm) work best with a 50mm knob. For larger internal or external doors, knobs up to 75mm diameter are appropriate, according to Period Home Style.
Where Can I Buy Door Knobs Online?
Top UK Retailers
Several UK specialists offer wide selections of door knobs. Screwfix provides complete sets with spindles and rollers, often with free delivery over a threshold. Hiatt Hardware stocks extensive ranges with a focus on UK-standard 8mm spindles. For period designs, From The Anvil offers heritage collections with British manufacturing credentials.
What to Look for in a Set
Check that the set includes two knobs, a spindle, and a latch. Many retailers list backset and door thickness compatibility clearly. Buildworld provides a comparative guide on finishes and mechanisms.
Buying a single knob without a spindle is a common mistake. Always order a pair (two knobs and a matching spindle) to ensure correct fit.
How Long Does It Take to Replace a Door Knob?
- 0 min: Gather tools: screwdriver, new knob set, possibly a drill.
- 2 min: Remove old knob: unscrew visible screws or detach rose plate.
- 5 min: Remove spindle and old latch/bolt mechanism.
- 8 min: Insert new latch and attach new spindle.
- 10 min: Place new knobs on spindle and secure with set screws.
- 12 min: Test operation; adjust screw tension if necessary.
- 15 min: Finished – dispose of old hardware.
What Are the Facts and Myths About Door Knobs?
| Claim | Status | Explanation |
|---|---|---|
| All door knobs are the same size. | Myth | Spindle length and backplate dimensions vary; measure before buying. |
| Door knobs can be used on any door thickness. | Myth | Most kits suit 35–45mm; thicker doors need extended spindles. |
| Brass door knobs are always better than steel. | Depends | Brass is durable and resists corrosion, but steel is stronger for high-traffic areas. |
| Replacing a door knob requires a professional. | Myth | It is a DIY task requiring only basic tools. |
How to Choose the Right Door Knob for Your Home
The choice depends on door type, interior style, and frequency of use. For period properties, porcelain or brass knobs add authenticity. Modern homes often pair matte black or chrome knobs with minimal decor. Wardrobe doors may use smaller knobs with shorter spindles. When replacing, always measure the existing backplate and spindle to ensure compatibility.
Online retailers like those mentioned offer wide ranges, but buying from a specialist with free delivery (e.g., Hiatt Hardware) can save on shipping costs. For the best price-performance ratio, consider screwfix sets which include all necessary parts.
What Expert Tips Are Available for Selecting Door Knobs?
A door knob should be firm but turn smoothly; any wobble indicates a loose set screw.
Hiatt Hardware product guide (paraphrased)
Porcelain knobs have been used since the Victorian era and remain a favourite for their cool touch and timeless appeal.
From The Anvil product description (adapted)
For bathrooms, choose a knob with a privacy lock function – usually a push-button or turn-lock on the rose.
Door Handle Company buying advice (summarised)
Next Steps After Choosing Your Door Knob
Measure your door thickness and backplate width. Select a finish that complements your existing hardware. Order a full knob set (including spindle and screws) to avoid missing parts. Install using a simple screwdriver — see the timeline above. If the knob feels loose after installation, tighten the grub screw on the underside. For more home improvement guidance, check out Consumer Unit – UK Regulations, Wiring & Best Brands 2025 and Hiking Shoes – Expert UK Buying Guide 2025.
Frequently Asked Questions
Can I use a door knob on an external door?
Yes, but ensure it has a lockable mechanism and is made of weather-resistant material like brass or stainless steel.
What does a door knob screwfix set include?
Typically two knobs, a spindle, a latch/case, and screws. Some sets include backplates or roses.
How do I measure a door knob?
Measure the backplate width, spindle diameter (usually 8mm), and overall knob projection from the door surface.
Are wooden door knobs durable?
Yes, if sealed properly, but they can absorb moisture in bathrooms. They offer a natural aesthetic but may require more maintenance than metal.
Why does my door knob keep coming loose?
The grub screw may need tightening; alternatively, the spindle could be worn. Replace the set if the spindle is stripped.
What size door knob do I need?
Standard internal doors use a 50mm knob. For larger doors, choose up to 75mm diameter.
What is the best finish for a high-traffic hallway?
Brass or stainless steel offers durability and easy cleaning. Matt black may show wear faster.
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