IP18 vs IP40
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP18 and IP40 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 1 vs 4) and liquid protection (level 8 vs 0). IP18 is rated for > 50 mm — back of hand and continuous immersion (manufacturer-specified), while IP40 provides > 1 mm — small wires and no protection.
The IP18 classification guarantees protection against solid objects larger than 50 mm and protection against the effects of continuous immersion in water under conditions specified by the manufacturer.. It is an IEC 60529 ingress protection code combining first-digit (solid) level 1 with second-digit (liquid) level 8.
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.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP18
1 — > 50 mm — Back of Hand
IP40
4 — > 1 mm — Small Wires
Liquid protection (second digit)
IP18
8 — Continuous Immersion (manufacturer-specified)
IP40
0 — No Protection
Dust-tight
IP18
No
IP40
No
Water-jet resistant
IP18
Yes
IP40
No
Submersible
IP18
Yes
IP40
No
Outdoor suitable
IP18
Yes
IP40
No
The exact difference (IP18 vs IP40)
Solid protection
IP18
Level 1 — > 50 mm — Back of Hand
IP40
Level 4 — > 1 mm — Small Wires
IP18 provides "> 50 mm — Back of Hand" (level 1), while IP40 provides "> 1 mm — Small Wires" (level 4). IP40 is 3 levels higher.
Liquid protection
IP18
Level 8 — Continuous Immersion (manufacturer-specified)
IP40
Level 0 — No Protection
IP18 provides "Continuous Immersion (manufacturer-specified)" (level 8), while IP40 provides "No Protection" (level 0). IP18 is 8 levels higher.
NEMA equivalents
No direct NEMA equivalent.
No direct NEMA equivalent.
Recommendation
IP18 offers higher overall protection than IP40. Choose IP18 for harsher environments; IP40 may suffice for milder conditions and can be more cost-effective.