Short answer: IP44 is enough for indoor or sheltered installations where the plug only meets splashing water. IP67 is required when the connector may be submerged, hosed down, or exposed to heavy rain, dust and washdown - construction sites, ports, food plants, and oil & gas. The price gap is usually 20-40%, so specifying IP67 everywhere wastes money, while specifying IP44 outdoors causes failures within months.
What the two digits actually mean
IEC 60529 defines the IP code. The first digit is solids, the second is water.
- IP44 - protected against solid objects over 1 mm (tools, wires) and against water splashing from any direction.
- IP67 - dust-tight (no dust ingress at all) and protected against temporary immersion in water, typically 1 m for 30 minutes.
The step from IP44 to IP67 is not cosmetic. It requires a gasket design that seals on the cable gland and the lid, a housing that will not deform under pressure, and contacts that stay aligned after repeated mating.
Which rating fits which site
- Indoor workshop, dry, no water - IP44
- Warehouse with occasional cleaning - IP44
- Covered yard, splash only - IP44 or IP54
- Open construction site, rain and mud - IP67
- Ports, cranes, shipyards - IP67
- Food and beverage washdown areas - IP67
- Oil & gas, petrochemical - IP67 (plus ATEX if hazardous zone)
- Temporary power distribution outdoors - IP67
The three mistakes buyers make
1. Reading IP44 as waterproof. It is splash-resistant, not water-resistant under pressure. A jet wash will get through.
2. Forgetting the mated pair. An IP67 plug in an IP44 socket is an IP44 connection. The rating applies to the assembly, not the single part. Always specify both halves at the same rating.
3. Ignoring cable gland quality. Most field failures at IP67 are gland failures, not housing failures. A cheap gland with a hard seal will leak after a few temperature cycles.
What drives the cost difference
IP67 versions use more material (thicker walls), a two-stage seal, and tighter moulding tolerances. In practice, factory cost is 20-40% higher than IP44 for the same current rating. On a 1,000-piece order that is real money, which is why matching the rating to the actual site matters more than ordering the highest spec available.
Frequently asked questions
Can I use an IP44 plug outdoors if it is under a roof? Yes, if it is genuinely sheltered from rain and never washed. If water can pool or spray, move to IP67.
Is IP67 the same as waterproof? No. IP67 covers temporary immersion (1 m, 30 min). Continuous submersion needs IP68.
Do IP67 plugs cost much more? Typically 20-40% more at factory level for the same rating, mainly from sealing design and material.
About Hefeng Electric - Hefeng Electric is a manufacturer of IEC 60309 industrial plugs, sockets and connectors in Fujian, China. More than 2,000 in-house moulds, CE (LVD + EMC), RoHS, ISO 9001 and ISO 14001. Contact: sales@electroconn.com