| NEMA Type 4X stainless-steel enclosure | Often 304 or 316 stainless steel | A properly rated enclosure provides Type 4 protection and corrosion protection. Stainless steel also offers a durable metal construction. | Grade, finish, welds, fasteners, and cleaning practices affect suitability. 316 is commonly considered for chloride exposure, but it is not immune to corrosion in every condition. | Food-processing areas, coastal installations, and washdown locations, subject to the specific environment and enclosure rating. |
| NEMA Type 4X fiberglass-reinforced enclosure | Molded fiberglass-reinforced polyester or a similar composite | Nonmetallic construction does not rust, and a Type 4X-rated model is designed for the stated enclosure protections. | Check UV resistance, impact performance, temperature limits, chemical compatibility, and mounting requirements for the specific product. | Outdoor control equipment, utility installations, and corrosive industrial environments where a nonmetallic enclosure is suitable. |
| NEMA Type 4X thermoplastic enclosure | Molded thermoplastics such as polycarbonate or other specified polymers | Nonmetallic, corrosion-resistant construction; some designs can be lightweight or allow viewing through a suitable cover. | Verify the exact resin’s chemical, UV, heat, and impact properties. A material alone does not establish a NEMA rating. | Instrumentation, sensors, and compact control equipment in applications matched to the selected polymer. |
| NEMA Type 4X coated-metal enclosure | Metal substrate with a specified protective coating system | Can combine a metal enclosure structure with a corrosion-protective finish when the complete enclosure is designed and rated accordingly. | Coating damage, cut edges, joints, and maintenance can affect corrosion resistance. Confirm the complete enclosure—not just the coating—has the required rating. | Industrial installations where a rated coated-metal design meets the site’s exposure and maintenance requirements. |
| NEMA Type 4 enclosure (comparison) | Various materials, depending on the enclosure design | Designed for Type 4 protection, including protection against windblown dust, rain, splashing water, and hose-directed water, and protection against external ice formation. | Unlike Type 4X, Type 4 does not add the Type 4X corrosion-resistance requirement. Check the applicable standard and product documentation. | Indoor or outdoor locations needing Type 4 protection where the additional Type 4X corrosion protection is not required. |