IP40 vs IP55
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP40 and IP55 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 4 vs 5) and liquid protection (level 0 vs 5). IP40 is rated for > 1 mm — small wires and no protection, while IP55 provides dust-protected and water jets (6.3 mm nozzle).
IP40 protects against small tools and wires (1 mm objects) but offers no water protection. Useful for indoor equipment needing finer ingress protection against small debris and tools.
IP55 is dust-protected and resists low-pressure water jets (6.3 mm nozzle, 30 kPa). A popular industrial rating for equipment exposed to dust and directed water spray but not immersion.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP40
4 — > 1 mm — Small Wires
IP55
5 — Dust-Protected
Liquid protection (second digit)
IP40
0 — No Protection
IP55
5 — Water Jets (6.3 mm nozzle)
Dust-tight
IP40
No
IP55
Limited
Water-jet resistant
IP40
No
IP55
Yes
Submersible
IP40
No
IP55
No
Outdoor suitable
IP40
No
IP55
Yes
The exact difference (IP40 vs IP55)
Solid protection
IP40
Level 4 — > 1 mm — Small Wires
IP55
Level 5 — Dust-Protected
IP40 provides "> 1 mm — Small Wires" (level 4), while IP55 provides "Dust-Protected" (level 5). IP55 is 1 level higher.
Liquid protection
IP40
Level 0 — No Protection
IP55
Level 5 — Water Jets (6.3 mm nozzle)
IP40 provides "No Protection" (level 0), while IP55 provides "Water Jets (6.3 mm nozzle)" (level 5). IP55 is 5 levels higher.
NEMA equivalents
No direct NEMA equivalent.
No direct NEMA equivalent.
Recommendation
IP55 offers higher overall protection than IP40. Choose IP55 for harsher environments; IP40 may suffice for milder conditions and can be more cost-effective.