Technical Knowledge Center
Cable Gland Selection: Diameter, Threads, IP and EMC
Choose cable glands by cable diameter, armour, thread, IP rating, material, EMC bonding and installation torque.
2026-11-02 · Updated November 2, 2026 · Reviewed for publication by the technical sourcing team · For project specification and compliance decisions, confirm the applicable local code and model-specific documents with the project engineer, certification body or inspection authority.
Match gland to cable
Confirm sheath diameter, armour, screen, sealing range, thread form, panel thickness and enclosure space. Metric, NPT and PG threads are not interchangeable.
Treat IP as an assembly result
Cable diameter, seal, hole, mounting surface, torque and installation quality affect the complete enclosure result. Gland marketing language alone is not proof of the installed IP rating.
Separate EMC and hazardous-area questions
An EMC gland may be needed for a specified shield-bonding design. Hazardous-area selection requires the appropriate IEC 60079 or local protection concept and certified assembly.
Avoid incorrect-size compensation
Do not over-tighten a nut to compensate for an incorrect sealing range. Follow the gland manufacturer’s torque and assembly instructions.
Standards and project evidence: what each layer proves
| Reference layer | Use in procurement | What to confirm | Buyer action |
|---|---|---|---|
| Cable construction | Controls gland type | Unarmoured, armoured or shielded | Match the exact cable |
| Thread | Controls enclosure fit | Metric, NPT or PG form | Confirm hole and pitch |
| Environment | Controls sealing and material | Outdoor, washdown, chemicals or hazardous area | Verify the complete assembly |
Frequently Asked Questions
How do I choose a cable gland size?
Measure the actual cable outside diameter and select a gland whose clamping range includes it.
Can M20 fit an NPT hole?
Do not assume so. Thread form and pitch must match.
Is IP68 always better than IP65?
They describe different tested conditions; choose the rating required by the installed environment.
Authoritative sources
Source note: standards and certification references describe the scope of the referenced documents. They do not certify every cable model offered by any supplier. Buyers should verify model-specific evidence before purchase.