Armored cable glands and the enclosure rating they leave you

Short answer: a gland its maker rates NEMA 4X, mounted in the hole its datasheet prints (0.875 in [22.2 mm] for a 1/2 in NPT thread), with the sealing washer flat and the armor clamped, leaves the panel's rating where it was. The assembly keeps the rating of the lowest-rated part in the wall, so you match the gland to the box and the rating survives the cut. Indoors changes the risk, never the rule. The warranty runs through the equipment maker's documented penetration instructions, so you drill where its drawing allows. The rest of this page keeps both claims true: the number on the wall and the paper in the file.

The rating follows the lowest part in the wall

Cut a hole and you own a piece of the wall. NEMA's enclosure FAQs state the weakest-link rule the way panel builders use it: an assembly keeps the rating of its lowest-rated part. A box rated NEMA 4X / IP66 by the manufacturer (that is how our stainless boxes are rated, and they are not UL listed) holds 4X when every hole carries a gland its maker rates 4X. Fit an IP54 gland into the same wall and the honest number for that panel is IP54, from the first thread in.

The X matters as much as the 4. Type 4X covers falling dirt, windblown dust, rain, sleet, snow, splashing water and hose-directed water, and the corrosion side is tested: NEMA 250 gives Type 4X another 200 hours of salt spray against a type 304 stainless specimen. A gland carrying the same claim was built to hold that line where the cable passes, so you buy gland and box at one rating. The article on what NEMA rating a panel keeps after you cut it and mount devices walks the same rule across switches and operators, and the NEMA 4 vs 4X vs IP66 guide holds the fundamentals.

The code side agrees. NEC 110.28 is explicit for US installations: an IP code does not replace an enclosure type rating. When your spec or your inspector leans on the type number, the gland needs the matching NEMA rating printed by its own maker, not only an IP66 mark.

What a 4X gland has to seal

An armored-cable gland holds four sealing jobs in one body. The clamping seal grips the outer sheath, and it only works inside the printed range; the cable gland clamping range article shows what happens at each edge of that range. The armor cone grips the steel wires and carries fault current into the body, and the grounding side of that joint is its own subject, covered in steel-wire armor grounding requirements under IEC and NEC. The sealing washer under the body or locknut closes gland-to-wall on flat metal. A barrier gland adds a fourth seal inside, on the inner sheath.

The number behind the mark is specific. IEC 60529 tests the second digit 6 with a 12.5 mm nozzle delivering 100 L/min from 2.5 to 3 m [8.2 to 9.8 ft] for at least 3 min, aimed from any practical angle. IP66 is therefore a hose rating, never an immersion rating; a pit that floods is a different design conversation, and the NEMA 4X vs 6P submersion comparison covers it.

Armor wicks water. Moisture that finds steel-wire armor travels along the gaps between the wires, which is the reason the inner barrier seal exists. On a dry indoor wall a single-seal armored gland is the normal fit; near washdown or floor flooding, specify the barrier type. Match the seal compound to your room as well: nitrile, about -30 to 120 C, for compressor-room oil mist, and EPDM, about -50 to 150 C, where water and caustic wash hit. Those are typical O-ring handbook values, and the datasheet of the gland you buy wins.

The hole: size, edge and where it goes

The gland datasheet prints the mounting hole, and that number settles the seal. A 1/2 in NPT grip takes 0.875 in [22.2 mm], the diameter UL 50's knockout and fitting-dimension table (Table 71-1A) prints for 1/2 in trade size, and a 3/4 in grip takes 1.109 in [28.2 mm]. Metric grips print metric holes, and the M20 gland hole size article carries those numbers. Cutting cleanly matters as much as diameter; the how to cut a hole in a stainless enclosure guide covers the tool sequence, and you deburr both faces so the washer bears on flat metal all the way round.

Location keeps the seal working for years. Put glands on the bottom wall where the layout allows, hold 2 in [50 mm] clear of corners, welds and the door-gasket track, and leave one hole diameter of flat metal between rims. That spacing is standard panel practice, and it keeps the wall from flexing between holes. An up-facing gland is the worst case even indoors; the cable glands facing up article shows the drip loop that rescues one when the layout leaves no other face. Whether the drilling itself costs you anything is its own question, answered in does drilling an enclosure affect its rating.

What indoors changes

Indoors changes what the room can throw at the wall, never the number on it. The box is rated 4X against hose-directed water whether the hose exists or not, and every hole you add takes its rating from the part you fit. So the indoor question is a buying decision: what must the whole assembly still claim after today?

• Room stays dry, the spec is silent and the type number lives on the nameplate only: an IP54 gland is honest, and the panel then carries IP54.
• Any washdown, misting or hose cleaning within reach: NEMA 4X glands, barrier type where the armor can carry water.
• The spec or the code table names the type: NEC Table 110.28 lists enclosure types by condition, so the 4X marking has to stay true, which means matched glands in every hole.
• The panel is a listed industrial control panel: UL 508A is the listing standard, NEC 409.110 puts the type number on the marking, and the cut goes through the panel builder so the listing file matches the metal.

Manufacturer ratings and UL listings are different papers, and the UL 50E vs NEMA 250 listing guide separates them cleanly. If choosing the box itself is your next step, the enclosure selector sorts the catalog by room conditions and usable size.

The warranty runs through the equipment instructions

The equipment's warranty answers to its manufacturer's instructions, and most makers publish where penetrations may go. Get that drawing before the drill touches metal: a compressor enclosure can hide refrigerant lines, oil piping and harnesses in walls that look empty, and one wrong hole is a refrigerant repair, not rework. Drill inside the marked zone, send the gland layout with your question when the drawing is silent, and keep the written reply in the job file.

Lock the machine out and prove the enclosure dead before cutting, then vacuum the chips out of the pan. Steel swarf across a live drive does damage no gland can undo.

The gland itself is rarely the warranty question. A 4X-rated gland mounted to its datasheet is a competent penetration in any equipment maker's book. What moves coverage is where the hole goes and what the drill meets on the way, and the drawing settles both.

Working one armored feed and five control cables through a 4X wall

Here is the whole decision on one panel, with each input labeled by where it comes from.

• Enclosure: a 20 x 16 x 8 in [508 x 406 x 203 mm] stainless box, rated NEMA 4X / IP66 by the manufacturer, not UL listed. A size inside our standard range; swap in your own.
• Power entry: one steel-wire-armored feed through a brass armored gland, 1/2 in NPT, rated 4X by its maker, with armor clamp and outer seal; mounting hole 0.875 in [22.2 mm] from its datasheet.
• Control entries: five cables of 4.8 mm [0.19 in] OD through nylon 6.6 grips whose printed clamping range is 4-6.4 mm [0.16-0.25 in] and whose maker rates them 4X (grip makers' published specifications).
• Layout: all six on the bottom wall, 2 in [50 mm] from the corners, 2 in between centers.

The rule in words: the panel keeps 4X when three checks pass. Every part in a hole carries a 4X rating from its maker, every cable sits inside its printed clamping range, and every washer bears on flat, deburred metal. The assembly rating is the lowest rating in the wall.

• Range check: 4 <= 4.8 <= 6.4 mm, so the grips fit with 1.6 mm [0.06 in] of room above and 0.8 mm [0.03 in] below.
• Hole check: 0.875 - 0.840 = 0.035 in [0.9 mm] of clearance around the 1/2 in NPT thread, 0.018 in [0.44 mm] a side, all closed by the washer on flat metal.
• Layout check: six holes at 2 in centers span (6 - 1) x 2 = 10 in; with 2 in at each end that uses 14 in of the 20 in width and leaves 6 in of slack for locknut wrenches.
• Rating check: the lowest-rated part in the wall is 4X, so the wall is 4X.

Result: the panel ships with its nameplate still true. Order one brass armored gland and five nylon 6.6 grips, specify six 0.875 in [22.2 mm] holes on the bottom wall at 2 in centers, and pick the washer compound for the room, nitrile beside oil mist or EPDM for wash. Step up a gland size the moment a cable OD leaves the printed range; a seal working at the edge of its range is the first place a 4X wall leaks.

What to put on the order

Six lines on the order stop the drilling from becoming a debate later:

• Gland rating: at least the box's, with the maker's NEMA 4X mark on every grip that has to hold a 4X panel.
• Thread and hole: 1/2 in NPT in a 0.875 in [22.2 mm] hole, or the metric pair your tooling prefers, taken from the gland datasheet.
• Seal compound: nitrile to about 120 C in oil-mist rooms, EPDM to about 150 C where water and caustic wash reach the panel.
• Barrier inner seal on any armored gland that can see water tracking along the armor.
• Hole count, wall and centers, laid out in the cutout designer, which exports the layout with your quote.
• The equipment maker's penetration drawing in the job file, for the warranty trail.

Lay the holes out before you order and the drawing that leaves with your quote already carries every opening at its datasheet size. The stainless enclosure size finder pairs the box with your panel, and custom work is delivered in 10 business days, counted from your approval of the drawing. Match the gland to the box, cut to the printed number, keep the washer on flat metal: that is the whole method, and the rating you ship is the rating you keep.

Catalog dimensions to compare

Compare these catalog dimensions with your component layout. Open each enclosure for its rating, material and usable space, then check those specifications against your application.

Questions