IP17 vs IP21
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP17 and IP21 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 1 vs 2) and liquid protection (level 7 vs 1). IP17 is rated for > 50 mm — back of hand and temporary immersion (up to 1 m), while IP21 provides > 12.5 mm — finger and vertically dripping water.
Built to withstand protection against solid objects larger than 50 mm and protection against the effects of temporary immersion in water. Ingress of water in quantities causing harmful effects shall not be possible.. Classified as IEC 60529 ingress protection code IP17, it pairs solid level 1 with liquid level 7.
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.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP17
1 — > 50 mm — Back of Hand
IP21
2 — > 12.5 mm — Finger
Liquid protection (second digit)
IP17
7 — Temporary Immersion (up to 1 m)
IP21
1 — Vertically Dripping Water
Dust-tight
IP17
No
IP21
No
Water-jet resistant
IP17
Yes
IP21
No
Submersible
IP17
Yes
IP21
No
Outdoor suitable
IP17
Yes
IP21
No
The exact difference (IP17 vs IP21)
Solid protection
IP17
Level 1 — > 50 mm — Back of Hand
IP21
Level 2 — > 12.5 mm — Finger
IP17 provides "> 50 mm — Back of Hand" (level 1), while IP21 provides "> 12.5 mm — Finger" (level 2). IP21 is 1 level higher.
Liquid protection
IP17
Level 7 — Temporary Immersion (up to 1 m)
IP21
Level 1 — Vertically Dripping Water
IP17 handles Hydrostatic ~10 kPa at 1 m (Temporary Immersion (up to 1 m)), while IP21 handles 0.1 mm/min drip rate (Vertically Dripping Water). IP17 provides 6 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP17 offers higher overall protection than IP21. Choose IP17 for harsher environments; IP21 may suffice for milder conditions and can be more cost-effective.