IP21 vs IP39K
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP21 and IP39K are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 2 vs 3) and liquid protection (level 1 vs 9K). IP21 is rated for > 12.5 mm — finger and vertically dripping water, while IP39K provides > 2.5 mm — tool / wire and high-pressure, high-temp water jets.
Designed for environments requiring protection against solid objects larger than 12.5 mm and protection against vertically falling drops of water. Dripping water shall have no harmful effects., IP21 is an IEC 60529 code combining solid level 2 with liquid level 1.
IP39K is an ingress protection code that ensures protection against solid objects larger than 2.5 mm and resistance to high-pressure (8–10 MPa), high-temperature (80 °C) water jets. It is an IEC 60529 ingress protection code combining first-digit (solid) level 3 with second-digit (liquid) level 9K.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP21
2 — > 12.5 mm — Finger
IP39K
3 — > 2.5 mm — Tool / Wire
Liquid protection (second digit)
IP21
1 — Vertically Dripping Water
IP39K
9 — High-Pressure, High-Temp Water Jets
Dust-tight
IP21
No
IP39K
No
Water-jet resistant
IP21
No
IP39K
Yes
Submersible
IP21
No
IP39K
Yes
Outdoor suitable
IP21
No
IP39K
Yes
The exact difference (IP21 vs IP39K)
Solid protection
IP21
Level 2 — > 12.5 mm — Finger
IP39K
Level 3 — > 2.5 mm — Tool / Wire
IP21 provides "> 12.5 mm — Finger" (level 2), while IP39K provides "> 2.5 mm — Tool / Wire" (level 3). IP39K is 1 level higher.
Liquid protection
IP21
Level 1 — Vertically Dripping Water
IP39K
Level 9 — High-Pressure, High-Temp Water Jets
IP21 handles 0.1 mm/min drip rate (Vertically Dripping Water), while IP39K handles 8–10 MPa (High-Pressure, High-Temp Water Jets). IP39K provides 8 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP39K offers higher overall protection than IP21. Choose IP39K for harsher environments; IP21 may suffice for milder conditions and can be more cost-effective.