NEMA vs IP rating

NEMA rating can be compared with IP rating - although there is no direct correspondence - but the first one is more complete and also includes other factors such as the protection from corrosion.

NEMA PROTECTION 12 3R/4 4/4X
access to hazardous parts x x x
ingress of solid foreign objects (falling dirt) x x x
ingress of water (dripping and light splashing) x x x
ingress of water (rain, snow, and sleet)   x x
ingress of solid foreign objects (dust,lint, fibers, and flyings) x x x
oil and coolant seepage x    
ingress of water (Hosedown and splashing water)   x x
corrosive agents     x
IP EQUIVALENT IP 54 IP 56 IP 56