Cables and Fixings
Cable & Fixings Buying Guide
Choosing the right cable, fixing, and gland is essential for a safe, tidy, and reliable electrical installation. Whether you’re wiring a domestic property, installing outdoor feeds, or managing industrial circuits, understanding cable type, size, environment, and suitable fixings will save time and prevent problems.
For most home installations, Twin & Earth (T&E) cables handle lighting and socket circuits, while SWA (Steel Wire Armoured) cables are used for outdoor, underground, or exposed runs where mechanical protection is needed. Flexible cables are common for appliances and equipment, and fire-rated cables are required for emergency circuits such as fire alarms and smoke detectors.
Choosing the right fixing (clips or saddles) is just as important as the cable itself. Clips hold cables securely, prevent sagging, and ensure compliance with regulations. For SWA cables, using the correct armoured cable gland ensures proper earthing of the armour and maintains water/dust protection.
1) Common Cable Types & Uses
|
Cable Type |
Typical Use |
Environment |
Notes |
|
Twin & Earth (T&E) |
Lighting, sockets, small domestic circuits |
Indoor |
PVC insulation, standard domestic wiring |
|
SWA (Steel Wire Armoured) |
Main supply, outdoor runs, exposed circuits |
Indoor/outdoor, underground |
Armour provides mechanical protection & earthing |
|
Flexible Cable (NYM, PVC) |
Appliances, lighting, extension leads |
Indoor |
Flexible, easy to route |
|
Fire-Rated Cable (FP200/FP400) |
Emergency circuits, fire alarms |
Indoor |
Maintains circuits in fire |
|
Data / Coax / Ethernet |
TV, internet, networking |
Indoor/outdoor |
Shielded for outdoor use |
|
Heating / Trace Cable |
Electric underfloor heating |
Indoor/outdoor |
Must follow manufacturer ratings |
|
Armoured Flexible / Metal-Sheathed |
Industrial machinery, heavy-duty equipment |
Factory/workshop |
Combines flexibility with armour protection |
2) Recommended Cable Sizes
|
Use |
Cable Type |
Typical Size |
Notes |
|
Small lighting circuits |
T&E |
1.0–1.5 mm² |
Indoor, standard load |
|
General power sockets |
T&E |
2.5 mm² |
Up to 13A |
|
Cooker / shower |
T&E / SWA |
6 mm² / 10 mm² |
Heavy load, indoor/outdoor |
|
Long outdoor feed |
SWA |
+1 size (e.g., 4 mm² for socket) |
Reduce voltage drop |
|
Large industrial / main feed |
SWA |
16–50 mm² |
Outdoor, mechanical protection |
3) Cable Fixings – Clips & Saddles
|
Cable Type |
Recommended Fixing |
Notes |
|
T&E 1–10 mm² |
Plastic single cable clip |
Indoor, light duty, spaced ~300 mm |
|
T&E 10–25 mm² |
Plastic or heavy-duty saddle |
Indoor, light-medium duty |
|
SWA |
Cable clamps or saddles |
Mechanical protection; spaced ~300 mm |
|
Flexible appliance cable |
Adhesive clip or cable tie |
Light loads only, indoor |
|
Heavy-duty / outdoor |
UV-resistant metal or plastic saddle |
Exposed cables, SWA or large cables |
Tips: Clip should fit snugly but not pinch the cable. Heavy or outdoor cables should have more frequent, heavy-duty fixings.
4) Armoured (SWA) Cable Glands
|
Cable Size (3‑core typical) |
Gland Thread |
Gland Type |
Notes |
|
2.5 mm² |
M20 |
BW / CW |
Small feed, indoor/outdoor |
|
4 mm² |
M20 / M25 |
BW / CW |
Medium feed, check OD |
|
6 mm² |
M25 |
BW / CW |
Standard domestic |
|
10 mm² |
M25 / M32 |
CW recommended |
Cooker/shower feed |
|
16 mm² |
M32 |
CW recommended |
Medium-large SWA |
|
25 mm² |
M32 / M40 |
CW recommended |
Large feed |
|
50 mm² |
M40 / M50 |
CW recommended |
Extra-heavy SWA |
BW (Indoor / Dry) → Basic indoor gland, clamps armour
CW (Outdoor / IP66/68) → Sealed, weatherproof, clamps armour & sheath
Accessories: Locknut, shroud, earth tag, sealing washers
5) Quick Decision Flow
- Determine cable type:
- Armoured → SWA + gland
- Non-armoured → T&E, flexible cable, or fire-rated
- Check environment:
- Indoor dry → BW gland / standard plastic clips
- Outdoor/exposed → CW gland / heavy-duty UV-resistant clips
- Check cable size & load:
- Measure actual OD for clips/glands
- Match conductor size to load (amps)
- Fixings:
- Clips, saddles, or trunking based on cable type and weight
- Glands (if SWA):
- Select thread size M20–M50
- Ensure armour is properly earthed
6) Summary Table
|
Cable Type |
Size |
Fixing |
Gland |
Notes |
|
T&E |
1–2.5 mm² |
Plastic clips / light saddles |
N/A |
Indoor lighting & sockets |
|
T&E |
6 mm² |
Heavy-duty saddle |
N/A |
Cooker / shower |
|
SWA |
2.5–50 mm² |
Cable clamps / saddles |
BW / CW |
Indoor/outdoor main feeds |
|
Flexible appliance |
0.75–6 mm² |
Adhesive clip / trunking |
N/A |
Indoor appliances |
|
Fire-rated |
1–4 mm² |
Clips/trunking |
N/A |
Emergency circuits |