IP31 vs IP33
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP31 and IP33 are both IEC 60529 ingress protection codes, but they differ in liquid protection (level 1 vs 3). IP31 is rated for > 2.5 mm — tool / wire and vertically dripping water, while IP33 provides > 2.5 mm — tool / wire and spraying water (up to 60°).
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.
IP33 protects against tools and 2.5 mm objects plus spraying water up to 60° from vertical. A practical rating for indoor equipment subject to light spray or for sheltered outdoor fixtures.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP31
3 — > 2.5 mm — Tool / Wire
IP33
3 — > 2.5 mm — Tool / Wire
Liquid protection (second digit)
IP31
1 — Vertically Dripping Water
IP33
3 — Spraying Water (up to 60°)
Dust-tight
IP31
No
IP33
No
Water-jet resistant
IP31
No
IP33
No
Submersible
IP31
No
IP33
No
Outdoor suitable
IP31
No
IP33
No
The exact difference (IP31 vs IP33)
Solid protection
IP31
Level 3 — > 2.5 mm — Tool / Wire
IP33
Level 3 — > 2.5 mm — Tool / Wire
Both IP31 and IP33 share the same solid protection: > 2.5 mm — Tool / Wire.
Liquid protection
IP31
Level 1 — Vertically Dripping Water
IP33
Level 3 — Spraying Water (up to 60°)
IP31 handles 0.1 mm/min drip rate (Vertically Dripping Water), while IP33 handles 80 kPa (tube) / 50 kPa (nozzle) (Spraying Water (up to 60°)). IP33 provides 2 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
No direct NEMA equivalent.
Recommendation
IP33 offers higher overall protection than IP31. Choose IP33 for harsher environments; IP31 may suffice for milder conditions and can be more cost-effective.