IP40 vs IP31
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP40 and IP31 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 4 vs 3) and liquid protection (level 0 vs 1). IP40 is rated for > 1 mm — small wires and no protection, while IP31 provides > 2.5 mm — tool / wire and vertically dripping water.
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.
The IP31 rating offers protection against solid objects larger than 2.5 mm and protection against vertically falling drops of water. Dripping water shall have no harmful effects.. It is an IEC 60529 ingress protection code combining first-digit (solid) level 3 with second-digit (liquid) level 1.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP40
4 — > 1 mm — Small Wires
IP31
3 — > 2.5 mm — Tool / Wire
Liquid protection (second digit)
IP40
0 — No Protection
IP31
1 — Vertically Dripping Water
Dust-tight
IP40
No
IP31
No
Water-jet resistant
IP40
No
IP31
No
Submersible
IP40
No
IP31
No
Outdoor suitable
IP40
No
IP31
No
The exact difference (IP40 vs IP31)
Solid protection
IP40
Level 4 — > 1 mm — Small Wires
IP31
Level 3 — > 2.5 mm — Tool / Wire
IP40 provides "> 1 mm — Small Wires" (level 4), while IP31 provides "> 2.5 mm — Tool / Wire" (level 3). IP40 is 1 level higher.
Liquid protection
IP40
Level 0 — No Protection
IP31
Level 1 — Vertically Dripping Water
IP40 provides "No Protection" (level 0), while IP31 provides "Vertically Dripping Water" (level 1). IP31 is 1 level higher.
NEMA equivalents
No direct NEMA equivalent.
No direct NEMA equivalent.
Recommendation
IP40 and IP31 offer comparable overall protection; choose based on the specific protection dimension (dust vs. water) that matters most for your application.