How to Choose a Cable Gland - Thread, Range, IP?
A cable gland routes a cable into an enclosure sealed and mechanically relieved. This guide explains how to select by thread (metric and PG), the correct clamping range, strain relief to EN 62444 and the IP rating to EN 60529.
View cable glandsWhich thread and clamping range fits?
Selection starts at the enclosure: the gland thread must match the drilled hole. The metric ISO thread (M12 to M63) and the older PG conduit thread (PG7 to PG48) are the most common. Within one size, the clamping range defines which cable diameters are sealed and held securely.
The cable outer diameter must sit inside the stated clamping range, ideally near its centre. Too close to the lower limit and the sealing insert will not seal reliably; too close to the upper limit and there is no reserve for strain relief.
How does strain relief work?
Strain relief stops any pull on the cable from reaching the terminal. As the dome nut is tightened, a clamping cage or cone presses the sealing insert onto the cable sheath. EN 62444 defines tested retention forces and sorts glands into ranges A and B.
Range A means enhanced strain relief with a metal clamping cage, range B means standard strain relief through the sealing insert. The permitted retention force depends on cable diameter and typically ranges from about 100 N to over 500 N by size.
- Polyamide (PA6): light, corrosion-free and good value.
- Nickel-plated brass: robust and EMC-capable with conductive contact to the screen.
- Stainless steel V4A: for food, chemical and outdoor areas with high corrosion load.
- Always tighten the strain relief to the maker's torque figure.
Which IP rating do you need?
The IP rating to EN 60529 describes protection against solid objects (first digit) and water (second digit). For cable glands the second digit usually decides. Important: the rating only holds if clamping range and torque are respected.
- Round, undamaged cable sheaths seal best - grooves or scores break the seal.
- Fit blanking plugs of the correct rating into unused holes.
- Do not forget the lock nut and O-ring, or the whole entry loses its rating.
Frequently asked questions
What is the clamping range of a cable gland?
The clamping range states which cable outer diameters the gland seals and holds securely. The cable diameter should sit near the middle of the range so that sealing and strain relief both work.
What is the difference between M and PG threads?
M is the metric ISO thread with a defined pitch, for example M20 x 1.5. PG is the older conduit thread. Both are in use, but new installations usually specify metric.
What does the second digit of the IP rating mean?
It describes protection against water to EN 60529, from 4 (splashing) through 6 (jets) to 8 (continuous immersion). The first digit covers protection against solid foreign objects.
When do I need an EMC cable gland?
For screened cables, for example on frequency inverters or servo motors. The contact springs bond the cable screen all round to the enclosure and divert interference currents over a large area.
Looking for the right cable gland?
We supply glands in metric and PG threads in polyamide, brass and stainless steel - with tested strain relief to EN 62444 and ratings up to IP69.
Standard tested
Strain relief tested to EN 62444.
Sealed to IP69
Ratings from IP54 to IP69 available.
Full range
All threads from M12 to M63 in stock.
Expert advice
We help with clamping range and material.