Bulb Holder Types: Every Cap Fitting Explained (E27, B22, GU10 & More)

Have you ever stood in a lighting aisle — or scrolled through an online shop — holding a bulb you know worked before, only to find it refuses to fit your new fixture? You're not alone. With over 15 common bulb holder types in circulation across UK homes, getting the right cap fitting is one of the most overlooked yet most important decisions in any lighting project.

This guide covers every major bulb holder type — from the classic E27 Edison screw to the twist-lock GU10 — with a full comparison table, material breakdowns, real customer feedback, and a curated look at LEDSone's premium lamp holder collection. Whether you're a DIY enthusiast, an interior designer, or an electrician, this is the only lamp holder guide you'll need in 2026.

A bulb holder — also called a lamp holder, light socket, or cap fitting — is the component that physically secures your light bulb and connects it to your electrical supply. It does two critical jobs: holds the bulb firmly in place and transfers electricity safely from the wiring to the bulb's base.

Lamp holders are found in virtually every light fitting you own — table lamps, pendant lights, ceiling roses, wall lights, and floor lamps. They come in a range of materials (metal, ceramic, Bakelite, plastic), cap types (screw, bayonet, pin), and styles (vintage, industrial, modern) to match both technical requirements and interior aesthetics.

Getting the right one matters not just for functionality, but for safety. A mismatched holder and bulb can cause loose connections, overheating, and in worst cases, electrical faults.

Before diving into every individual type, it helps to understand the two dominant systems used in the UK and globally:

Edison Screw (ES) — The bulb screws clockwise into the holder using a threaded metal base. Originated with Thomas Edison in the late 1800s. The letter "E" followed by a number (e.g. E27) indicates the thread diameter in millimetres. Dominant globally and increasingly the standard for LED retrofit bulbs.

Bayonet Cap (BC) — The bulb pushes in and twists a quarter-turn to lock using two side pins. Identified by the letter "B" followed by its diameter (e.g. B22). The traditional UK standard, still found in millions of British homes and widely available at LEDSone.

The E27 is the world's most common lamp holder. The "27" refers to the 27mm diameter of the screw thread. In the UK and Europe it's called ES (Edison Screw); in North America the equivalent is the E26 (26mm).

Best for: Pendant lights, table lamps, floor lamps, ceiling fixtures, vintage filament bulbs, LED retrofit bulbs.

Voltage: AC 110V–250V | Max Wattage: Typically 60W–100W

LEDSone stocks an exceptional range of E27 holders across every material and finish — from budget plastic to premium metal alloy vintage styles. Their Vintage E27 Metal Lamp Holder for Antique Filament Bulbs is one of their bestsellers with 29 five-star reviews, offered at just £4.89. Their E27 Industrial Lamp Light Bulb Holder comes in chrome and is particularly popular for exposed industrial-style pendant installations.

Available E27 finishes at LEDSone: Matt Black, Copper, Antique Brass, Chrome, Rose Gold, Satin Nickel, White, French Gold, Yellow Brass, Green Brass — over 20 colour options across 47+ E27 products.

The B22 (22mm diameter) is the classic British bayonet fitting — the push-and-twist cap that has been the UK residential standard for over a century. It's equally popular in Australia, New Zealand, and parts of Asia and Africa.

Best for: Traditional UK ceiling lights, wall fittings, table lamps, pendant lights.

Voltage: AC 110V–240V | Max Wattage: 60W

LEDSone's B22 Bayonet Brass Lamp Holder in a warm brass/copper finish brings a premium vintage aesthetic to standard bayonet fittings, starting from £3.60. Their self-locking B22 variant with ceramic core adds extra heat resistance — ideal for incandescent and halogen bulbs.

The E14 is the smaller sibling of the E27, with a 14mm thread diameter. Known in the trade as SES (Small Edison Screw), it's the fitting of choice for decorative and compact bulbs.

Best for: Chandeliers, wall sconces, decorative pendant lights, candle bulbs, small table lamps.

Voltage: AC 110V–250V | Max Wattage: 60W

LEDSone offers both white and black E14 holders from as little as £1.49 — the White E14 Lamp Holder for Pendant Lights has earned 9 verified reviews and is made from heat-resistant plastic with a 39mm ring thread for easy lampshade attachment.

The GU10 uses a push-and-twist mechanism with two pins spaced 10mm apart and a mains voltage (230V) supply. It's the standard fitting for recessed downlights, track lighting, and spotlights in modern UK homes.

Best for: Kitchen spotlights, bathroom downlights, track lighting, display lighting.

Voltage: 230V mains | Max Wattage: 50W (halogen) / 7W–10W (LED equivalent)

The GU10 is perhaps the most widely installed fitting in UK new-builds built since 2000. LEDSone's wider accessories range and compatible LED GU10 bulbs make this a popular category for renovation projects.

The MR16 (also called GU5.3) is a low-voltage 12V spotlight fitting with two pins spaced 5.3mm apart. Popular in older UK homes installed before GU10 became standard, they require a transformer or LED driver.

Best for: Older recessed spotlight systems, track lighting, accent displays.

Voltage: 12V AC | Max Wattage: 50W (halogen) / 5W–7W (LED)

The material of your lamp holder determines its heat tolerance, durability, and aesthetic. Here's what LEDSone stocks and when to choose each:

LEDSone's most popular category — 31 metal holder variants — spanning industrial chrome, antique brass, copper, satin nickel, and matt black. Metal holders offer the best durability and the richest visual finish for exposed bulb designs. Ideal for vintage Edison filament bulbs and industrial pendant lighting.

Choose metal when: You want a premium finish for an exposed fitting, industrial or vintage-style decor, or a long-lasting fixture.

Ceramic (porcelain) holders are the heat-resistant champions. LEDSone's ceramic E27 range (White Ceramic E27 60W) is rated for AC110V–250V and made from heat-resistant porcelain bonded with a metal shell. They're the only safe choice for applications using high-wattage incandescent bulbs, heat lamps, or reptile lighting.

Choose ceramic when: Your application generates significant heat, or you're using bulbs above 40W on a sustained basis.

Bakelite is an early thermoplastic with excellent electrical insulation and a classic black finish. LEDSone's 11 Bakelite holder variants give an authentic retro look that no modern plastic can replicate. Bakelite holders are fully compatible with modern wiring standards.

Choose Bakelite when: You want a genuine vintage aesthetic for restoration projects, exposed ceiling installations, or period-style interiors.

Lightweight, affordable, and available in bulk packs — LEDSone's plastic E27 and E14 holders use heat-resistant compounds that safely handle up to 60W. Their 5-pack E27 White Pendant Holders with Ring at £5.39 is outstanding value for DIY projects, replacing damaged sockets, or wiring up new pendant clusters.

Choose plastic when: Budget is a priority, you need multiple holders for a project, or for standard wattage LED applications.

1. What bulb cap type do you have?

Check the base of your existing bulb. E27 = large screw. E14 = small screw. B22 = two side pins, push-and-twist. GU10 = two pins, twist-lock. Match the holder to the bulb cap exactly.

2. What wattage will you run?

For LED bulbs under 15W, any holder material is suitable. For halogen or incandescent bulbs above 40W, opt for ceramic or metal holders to handle the heat safely.

3. Indoor or outdoor?

For outdoor or damp locations (bathrooms Zone 1 & 2), you need a holder rated to IP44 or higher. Standard indoor holders are not waterproof.

4. What aesthetic do you want?

For exposed visible holders in pendant or bare-bulb designs, choose metal or Bakelite for the best visual finish. For hidden holders inside shades or enclosed fittings, plastic is perfectly appropriate.

5. Do you need a shade ring or cord grip?

Pendant applications benefit from holders with built-in cord grips (protects wiring from strain) and shade rings (to attach lampshades). LEDSone labels these clearly on each product listing.

This is the most commonly asked question in UK lighting forums — and the honest answer is: both are excellent, but for different reasons.

Interior design trends are heavily influencing which lamp holder styles sell best this year: