Short answer: order IP65 — in practice a NEMA 4X / IP66 stainless box — whenever the worst that hits it is a hose. IEC 60529 proves digit 5 with a 6.3 mm [1/4 in] nozzle at 12.5 L/min [3.3 gal/min] from 2.5-3 m [8-10 ft] for at least 3 min, and digit 6 raises that jet to 12.5 mm at 100 L/min. Step up to IP67 only where the box can sit in water: 1 m [39 in] deep for 30 min. And no, the tighter seal does not cook your electronics — the price of digit 7 is gasket compression and stricter glands, never heat.
What is the real difference between IP65 and IP67?
The first digit is the same 6 in both codes — dust-tight, no ingress of dust — so the whole difference is the second digit: IP65 stops water jets from a 6.3 mm [1/4 in] nozzle at 12.5 L/min, and IP67 survives temporary immersion at the depth in the table below.
| What is tested | IP65 | IP67 |
|---|---|---|
| Solids, first digit | 6 — dust-tight, no ingress | 6 — dust-tight, no ingress |
| Water, second digit | 5 — jets from any direction | 7 — temporary immersion |
| Test hardware | 6.3 mm nozzle, held 2.5-3 m away | still water, top 0.15 m [6 in] under |
| Flow and pressure | 12.5 L/min at 30 kPa at the nozzle | none — the depth does the work |
| Duration | at least 3 min | 30 min |
| Depth | none | 1 m to the bottom face |
| Typical duty | rinse lines, spray, hose washdown | pits, ponded pads, floods, brief submersion |
These are two parallel tests, not rungs on one ladder: digit 7 never re-tests the jet, and digit 5 says nothing about being underwater. Because the first digit is shared, dust protection — flour, grain dust, pollen — is identical on both, so you are choosing on water alone. If the codes are new to you, what IP rating codes mean walks each digit; if you are weighing jet sizes instead, the IP65 vs IP66 water jet comparison shows what the bigger nozzle adds.
Does an IP67 enclosure heat up faster than IP65?
No. Both codes describe the same closed, ventless box, so your temperature rise comes from the watts inside and the steel outside — the arithmetic lands on one number whichever digit is printed on the label.
On a motor this question has an edge, because stepping to IP67 can change the shaft seal, and a shaft seal rubs. Your panel has no rubbing seal: the door gasket stands still, adds no friction and no watts, so it adds no degrees.
Run the numbers for a 20 x 16 x 8 in [508 x 406 x 203 mm] wall-mount box carrying a compact drive and its supplies at 50 W total:
- Surface: 2 x (0.508 x 0.406 + 0.508 x 0.203 + 0.406 x 0.203) = 0.78 m² [8.4 ft²]
- Shed rate: about 5 W per m² per C by natural convection and radiation off a light surface
- Rise: 50 ÷ (0.78 x 5) = 13 C
- At 35 C [95 F] ambient, everything inside sits near 48 C [118 F]
Relabel that same box IP67 and you recompute nothing. What does move the number: 100 W doubles the rise to 26 C, and full sun on a stainless face adds roughly 10 C of its own. When 48 C crowds your drive's limit, the fix is more surface or a heat path to the wall — sizing a VFD enclosure and PCB heat in a sealed enclosure cover both moves.
Which rating do you order for a washdown area?
IP65 already passes hose cleaning, but the better washdown order is NEMA 4X / IP66: a plant rinse hose behaves like digit 6 — a 12.5 mm nozzle at 100 L/min — far more than the 6.3 mm, 12.5 L/min jet of digit 5.
IEC 60529 aimed digit 5 at spray and rinse, and it holds that duty. In practice you will stand closer than 2.5 m [8 ft] with a hose pushing well past 12.5 L/min, which is the jet of digit 6, not digit 5. Every wall-mount and HMI enclosure we build in 304 and 316L is rated NEMA 4X / IP66 by the manufacturer — not UL listed — so one box clears both jet tests; the stainless size finder filters them by grade and size. For the jet-to-jet detail, IPX5 vs IPX6 for washdown settles it.
When do you actually need IP67?
Order IP67 when the box can end up under standing water even briefly: a sump or pit box, a washdown pad that ponds, a below-grade junction box in a flood zone, dock hardware — anywhere the immersion test describes a real shift.
| Where the box lives | What to order |
|---|---|
| Dry indoor panel room | IP54; step to IP65 in dust-heavy plants |
| Rinse or hose washdown | NEMA 4X / IP66 |
| Outdoor wall, rain and storm spray | NEMA 4X / IP66, 316L near the coast |
| Pit, sump or pad that ponds or floods | IP66 / IP67, dual-marked |
| Deeper or longer than the digit 7 test | IP68, with depth and time in writing |
Past that depth or duration you are buying IP68, where the depth and time are agreed with the maker and printed on the rating — why IP68 immersion ratings carry depth and time limits explains that step.
Does IP67 include the hose-down test?
No. IEC 60529 treats every second digit as its own test, so a box marked only IP67 has been immersed and was never sprayed; when one site sees hoses and floods, order the dual marking IP66 / IP67.
A dual marking means one physical enclosure passed both tests and both codes appear on the label. Ask for it in writing on the quote; it is the cheapest insurance on a pad that gets hosed at shift end and floods in a storm.
Is an IP67 door harder to live with?
Yes, a little. Holding back a flood takes a gasket compressed all the way around a flat seam, so an IP67 door closes firmer, its latches carry more load, and the seal deserves an eye at every service visit.
The water load itself is modest — a metre of standing water is about 10 kPa [1.5 psi], and on the 0.21 m² [2.3 ft²] face of a 20 x 16 in door that is roughly 2000 N [450 lbf] seating the door harder while the flood lasts. The engineering lives in the seam: door flatness and gasket compression and foam versus rubber door gaskets decide whether the seal holds for years, not the digit on the datasheet.
How do IP65 and IP67 map to NEMA 4X?
NEMA's published conversion table sets Type 4 and Type 4X against IP66 — one step past IP65 on jets — and puts IP67 alongside the submersion types, 6 and 6P, so the two systems overlap without matching.
NEC 110.28 keeps the systems separate for US installations: an IP code alone never satisfies a spec written in enclosure types, so put both on the drawing — Type 4X with IP66 for washdown, IP67 beside the submersion type. NEMA publishes the types and the conversion; it does not test or certify any enclosure. The rating on a box is its maker's statement — ours are rated by the manufacturer and not UL listed — and the NEMA 4 vs 4X vs IP66 guide with the IP rating chart carry the full tables.
What should you put on the order?
Four lines do it: the code with its test basis, glands that match the digit, a dual marking where hoses and floods coexist, and the depth and time once water can go beyond the immersion test.
- Rating wording. NEMA 4X / IP66 by the manufacturer for every hose, rain or washdown duty; our stainless boxes are cut to your drawing and delivered in 10 business days from your approval of the drawing.
- Glands and breathers. Match the digit or beat it. A box seals to the level of its weakest opening, and a 6.3 mm jet at 12.5 L/min will find a cheap IP54 gland in the first washdown.
- Dual marking. IP66 / IP67 on one label where the pit box also gets hosed.
- Depth and time. Once water can go deeper or stay longer than digit 7 allows, write IP68 and the numbers beside it.
For immersion duty, take those test numbers through the enclosure selector, which hands them to a custom quote along with your sizes and cutouts. For nine enclosures in ten the decision lands the same way: NEMA 4X / IP66 for everything a hose can touch, and IP67 for the one box that can drown.
Enclosures for this job
Catalog sizes that suit the job this article answers, picked from its subject; open one for its full specifications.
| Enclosure | Material | Outside H x W x D / display | Rating |
|---|---|---|---|
| 20 × 16 × 8 in | 304 stainless | 20 x 16 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 16 × 12 × 8 in | 304 stainless | 16 x 12 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 24 × 20 × 8 in | 304 stainless | 24 x 20 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 30 × 24 × 10 in | 304 stainless | 30 x 24 x 10 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
Questions
What does IP66 / IP67 on one label mean?
Both water tests passed on the same enclosure: the 12.5 mm, 100 L/min jet test and the immersion test. Buy that marking when one box faces hoses and floods in the same spot, and check the label prints both codes, since a lone 7 says nothing about jets.
Do cable glands need to match the enclosure rating?
Yes, or beat it. An enclosure seals to the level of its weakest opening, so an IP67 box fitted with IP54 glands is an IP54 box the moment a 6.3 mm jet at 12.5 L/min finds them. Order glands at the enclosure digit or higher and tighten them to the torque the gland maker prints.
Will an IP67 enclosure stop condensation?
No. A tighter seal traps the moisture already inside, and condensation forms the moment the panel cools below its dew point — about 17 C when the box holds 25 C air at 60% relative humidity. A breather drain rated IP66 or better equalizes the pressure and sheds the drip.
Is IP67 overkill for a wall-mounted outdoor panel?
Usually. Driven rain and storm spray stay below the IP65 jet test, so a NEMA 4X / IP66 box already carries margin on a wall. Save IP67 for boxes that can be submerged — a pit box in a flood zone holding 1 m of water for 30 min is the classic case.
