IP51 vs IPX4
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP51 and IPX4 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 5 vs 0) and liquid protection (level 1 vs 4). IP51 is rated for dust-protected and vertically dripping water, while IPX4 provides no protection and splashing water (all directions).
With IP51, an enclosure receives dust-protected (limited ingress, no harmful deposit) 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 5 with second-digit (liquid) level 1.
IPX4 (solid protection not specified) resists splashing water from any direction. A common minimum for bathroom and outdoor-covered appliances where dust sealing is not required.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP51
5 — Dust-Protected
IPX4
0 — No Protection
Liquid protection (second digit)
IP51
1 — Vertically Dripping Water
IPX4
4 — Splashing Water (all directions)
Dust-tight
IP51
Limited
IPX4
No
Water-jet resistant
IP51
No
IPX4
No
Submersible
IP51
No
IPX4
No
Outdoor suitable
IP51
No
IPX4
Yes
The exact difference (IP51 vs IPX4)
Solid protection
IP51
Level 5 — Dust-Protected
IPX4
Level 0 — No Protection
IP51 provides "Dust-Protected" (level 5), while IPX4 provides "No Protection" (level 0). IP51 is 5 levels higher.
Liquid protection
IP51
Level 1 — Vertically Dripping Water
IPX4
Level 4 — Splashing Water (all directions)
IP51 handles 0.1 mm/min drip rate (Vertically Dripping Water), while IPX4 handles 50–100 kPa (Splashing Water (all directions)). IPX4 provides 3 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
No direct NEMA equivalent.
Recommendation
IP51 offers higher overall protection than IPX4. Choose IP51 for harsher environments; IPX4 may suffice for milder conditions and can be more cost-effective.