Buyers often focus on the cable gland body and ignore the washer. In real installations, the washer is the part that seals the contact between the gland and the enclosure wall. Without it, a good gland can still leak at the panel side.
Panel surfaces are not always perfect
Sheet metal holes may have burrs, paint thickness, scratches or small deformation after punching. A suitable washer helps absorb these surface differences and creates a more even seal.
Washer material should match the environment
Standard rubber washers work for many general applications. For oil, heat, chemical exposure or outdoor aging, material selection should be reviewed. The washer must stay elastic long enough for the expected service environment.
Do not reuse damaged washers
During maintenance, washers can become compressed, cracked or cut by hole edges. Reusing a damaged washer can create a leak path even when the gland and cable size are correct.
Ordering suggestion
When buying cable glands for outdoor cabinets, order matched washers, locknuts, stopping plugs and reducers at the same time. This reduces missing parts during installation.