U.S. imports of parts for industrial temperature-treatment machinery and equipment (HS 841990) totaled $272.6M in August 2026, imported from 73 countries.
Importers of Parts for Industrial Temperature-Treatment Machinery and Equipment paid $41.4M in duties in August 2026, an effective tariff rate of 15.17% of the $272.6M imported — duty actually collected as a share of that value, not the published tariff schedule. Parts for Industrial Temperature-Treatment Machinery and Equipment imports of $272.6M in August 2026 ran 35% above the year-to-date monthly average of $202.2M.
Last updated: August 2026 dataReplacement and service parts for industrial machinery that treats materials through heating, cooling, or other temperature change — including heat exchangers, sterilizers, water heaters, and pulp-and-paper processing equipment — are classified here when not more specifically provided for elsewhere. China is the leading supplier, followed by Mexico and Canada, making Section 301 tariff exposure a recurring landed-cost concern for MRO buyers and OEM service networks. The heading's ten US tariff lines segment parts by end-use equipment type, so correct classification requires identifying the parent machine rather than the part's own material or function. Importers sourcing sterilizer components should note that parts for medical or surgical sterilizers (8419905040 and 8419909540) occupy dedicated lines with distinct duty treatment.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
8.2K shipments/mo
Classification within 841990 is driven by the identity of the parent machine, not the part itself. An importer must first classify the complete machine (e.g., a heat exchanger under 8419.50, a sterilizer under 8419.20) and then select the corresponding parts line. Supporting documentation such as OEM part numbers, technical drawings, or a letter from the manufacturer identifying the parent equipment is advisable.
Yes, parts classified under 841990 and imported from China are generally subject to Section 301 tariffs. Given that China is the leading source for many of these components, importers should evaluate whether product exclusions have been granted for specific part types and whether alternative sourcing from Mexico or Canada — both significant suppliers — could reduce trade-remedy exposure.
HSChapter 84
Subheading 2 of 14 in heading 8419
Subheading 841990 · $272.6M of $1.2B
ImportsExports
Imports
$272.6MYoY · free account
Exports
$80.6MYoY · free account
12-mo low · imports
YoY · free accountOver the twelve months to August 2026, the U.S. imported $2.1B of Parts for Industrial Temperature-Treatment Machinery and Equipment.
Through August 2026. Source: U.S. Census Bureau.
HS10 import codes under this HS6 parent, each with its own page. Source: U.S. Harmonized Tariff Schedule.
| Code | Description | Import Value | Effective Tariff % | Dutiable Share | Duty Collected |
|---|---|---|---|---|---|
| 8419903000 | Parts of Heat Exchange Units, Industrial | $119.5M | 11.31% | 74.40% | $13.5M |
| 8419909580 | Parts,Mach,Plant Equip,Treat Materl,Temp Chg,NESOI | $115.3M | 20.05% | 86.97% | $23.1M |
| 8419909520 | Parts of Equip for Restaurants,Etc, Temp Change | $15.5M | 16.36% | 89.42% | $2.5M |
| 8419901000 | Parts of Instantaneous or Storage Water Heaters | $11.2M | 9.12% | 49.04% | $1.0M |
| 8419908500 | Electromechanical Hand Tool Parts, NESOI | $4.2M | 11.12% | 96.56% | $467K |
| 8419902000 | Parts of Mach & Plant for Making Pulp,Paper,Papbrd | $3.1M | 13.05% | 87.03% | $407K |
| 8419905040 | Parts of Medical, Surgical or Laboratory Sterilize | $3.0M | 7.17% | 58.03% | $214K |
| 8419905080 | Prts,Mach,Treat Materl,Temp Chg,of Acryl Acd React | $623K | 9.87% | 85.70% | $61K |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
Import lines come from the U.S. Harmonized Tariff Schedule and export lines from Schedule B. The two are numbered by different agencies, so the same 10-digit code can appear in both tables describing a different product.
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Imports · August 2026
origin
China and Taiwan together supply 47% of it. China pays 36.0% duty; Mexico 0.5%.
customs district
destination
entry
rate provision · imports
18.4% enters free of duty; duty collected equals 15.17% of total import value.