SWA Cable Gland Calculator
Select the correct gland size for steel wire armoured cables
Reference Info & Formulas
CW Gland
Indoor use only. IP54 rated. Most economical option for dry, sheltered enclosures.
BW Gland
Outdoor / weatherproof. IP66 rated with integral seal. Standard choice for external installations.
E1W Gland
Hazardous areas. IP66 rated with barrier. Required for ATEX-rated installations (Zone 1/2, Zone 21/22).
S vs L: S = small entry, L = large entry. Same thread size but different cable OD ranges.
Torque: Always use a torque wrench for the inner seal nut to achieve the rated IP protection.
Shrouds: Add a gland shroud on outdoor installations for additional UV and weather protection.
Data: CMP Products / Prysmian cable data, BS 5467
For guidance only. The responsibility for any electrical installation lies with the qualified person carrying out the work. Always verify calculations independently and apply professional judgement.
How This Calculator Works
SWA cable gland selection is a lookup process based on the cable's outer diameter, which varies by conductor size and number of cores.
The calculator first looks up the base outer diameter for a 2-core cable of the selected size from BS 5467 data. For 3, 4, or 5-core cables it adds an approximate increase based on the additional conductors. It then matches the resulting OD against manufacturer gland ranges to find the correct gland size.
The thread size (M20, M25, etc.) determines the enclosure knockout required, while the S/L suffix indicates whether the small or large entry version is needed for the cable diameter.
Gland Size Quick Reference
Common SWA cable gland selections (2/3-core)
CMP Products / BS 5467| Cable (mm²) | Approx. OD (mm) | Gland Size | Thread |
|---|---|---|---|
| 1.5 - 4 | 12 - 16 | 20S | M20 |
| 6 - 10 | 15 - 19 | 20S / 20L | M20 |
| 16 | 19 - 21 | 20L | M20 |
| 25 | 22 - 24 | 25S | M25 |
| 35 | 24 - 26 | 25L | M25 |
| 50 | 28 - 30 | 32S | M32 |
| 70 | 31 - 33 | 32L | M32 |
| 95 | 35 - 38 | 40S | M40 |
| 120 | 38 - 41 | 40L | M40 |
| 150 - 185 | 43 - 48 | 50S / 50L | M50 |
| 240 - 300 | 52 - 60 | 63S / 63L | M63 |
OD varies with core count. 4/5-core cables may require the next size up. Always verify against the actual cable datasheet.
Installation Best Practices
Earth Continuity Through the Gland
Correct Armour Preparation
IP Rating Depends on Correct Installation
Frequently Asked Questions
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