Chapter 84 is the core chapter in the HS classification system for mechanical appliances, machinery and their parts, covering everything from power machinery (such as internal combustion engines and steam turbines) to various processing machines, office equipment, automatic data processing equipment, etc. This chapter emphasizes the mechanical function and power attributes of goods, rather than material or use. For parts classification, it is necessary to determine whether they are dedicated to a certain type of machine; if they are general-purpose parts, they may be classified under other chapters. 8409 is located in the internal combustion engine parts section of this chapter and specifically refers to parts used for spark-ignition or compression-ignition internal combustion engines. Heading 8409 covers parts specially designed or principally used for heading 8407 (spark-ignition reciprocating or rotary piston internal combustion engines) and 8408 (compression-ignition piston internal combustion engines, i.e. diesel engines). These parts must have identifiable mechanical characteristics and cannot be classified under other headings. Common parts include cylinder blocks, cylinder heads, pistons, connecting rods, injectors, fuel pumps, valves, crankshafts, etc. Note, however, that certain electrical components (such as starters and generators) are classified under Chapter 85, while general fasteners are classified according to material. Code 840999 is a 6-digit subheading: the first 2 digits "84" represent Chapter 84 (mechanical appliances, machinery); digits 3-4 "09" represent heading 8409 (parts specially designed or principally used for internal combustion engines); digits 5-6 "99" represent subheading 840999, namely "other" diesel engine parts. Specifically, under 8409, goods are first divided by internal combustion engine type into 840910 (aircraft engine parts), 840991 (spark-ignition engine parts), and 840999 (other, i.e. compression-ignition engine parts). Therefore, 840999 specifically refers to diesel engine parts, but does not include specific parts already listed under other subheadings (such as fuel pumps and injectors, which may be classified under 8413, etc.). This commodity is a diesel engine part. Since a diesel engine is a compression-ignition internal combustion engine, its dedicated parts should be classified under 8409. Under 8409, spark-ignition engine parts are classified under 840991, while diesel engine parts are classified under 840999. If the part is a general mechanical component (such as a bearing or gear), it may be classified under other headings of Chapter 84 or according to material. In addition, if the part is an electrical component (such as a starter), it should be classified under Chapter 85. Therefore, 840999 is the correct classification for dedicated non-electrical diesel engine parts.
Chapter
Chapter 84 is the core chapter in the HS classification system for mechanical appliances, machinery and their parts, covering everything from power machinery (such as internal combustion engines and steam turbines) to various processing machines, office equipment, automatic data processing equipment, etc. This chapter emphasizes the mechanical function and power attributes of goods, rather than material or use. For parts classification, it is necessary to determine whether they are dedicated to a certain type of machine; if they are general-purpose parts, they may be classified under other chapters. 8409 is located in the internal combustion engine parts section of this chapter and specifically refers to parts used for spark-ignition or compression-ignition internal combustion engines.
Heading
Heading 8409 covers parts specially designed or principally used for heading 8407 (spark-ignition reciprocating or rotary piston internal combustion engines) and 8408 (compression-ignition piston internal combustion engines, i.e. diesel engines). These parts must have identifiable mechanical characteristics and cannot be classified under other headings. Common parts include cylinder blocks, cylinder heads, pistons, connecting rods, injectors, fuel pumps, valves, crankshafts, etc. Note, however, that certain electrical components (such as starters and generators) are classified under Chapter 85, while general fasteners are classified according to material.
Digit Breakdown
Code 840999 is a 6-digit subheading: the first 2 digits "84" represent Chapter 84 (mechanical appliances, machinery); digits 3-4 "09" represent heading 8409 (parts specially designed or principally used for internal combustion engines); digits 5-6 "99" represent subheading 840999, namely "other" diesel engine parts. Specifically, under 8409, goods are first divided by internal combustion engine type into 840910 (aircraft engine parts), 840991 (spark-ignition engine parts), and 840999 (other, i.e. compression-ignition engine parts). Therefore, 840999 specifically refers to diesel engine parts, but does not include specific parts already listed under other subheadings (such as fuel pumps and injectors, which may be classified under 8413, etc.).
Classification Basis
This commodity is a diesel engine part. Since a diesel engine is a compression-ignition internal combustion engine, its dedicated parts should be classified under 8409. Under 8409, spark-ignition engine parts are classified under 840991, while diesel engine parts are classified under 840999. If the part is a general mechanical component (such as a bearing or gear), it may be classified under other headings of Chapter 84 or according to material. In addition, if the part is an electrical component (such as a starter), it should be classified under Chapter 85. Therefore, 840999 is the correct classification for dedicated non-electrical diesel engine parts.
📝 Declaration Elements
Product Name: The specific name of the declared commodity, which should accurately reflect the function of the part, such as "diesel engine cylinder head", "diesel engine injector nozzle", etc. Use: Explain what kind of machine the part is suitable for, such as "used for marine diesel engines", "used for generator set diesel engines", etc. Material: The main material of the declared part, such as cast iron, aluminum alloy, alloy steel, etc., which affects classification and customs valuation. Brand: Fill in the manufacturer or brand name; if there is no brand, fill in "no brand". Model: The model or specification of the part, used to distinguish the specific part and facilitate customs inspection. Applicable Engine Type: Clearly state whether it is compression-ignition (diesel) or spark-ignition; only diesel engines can be classified under 840999. Whether General-Purpose Part: Explain whether the part is dedicated to diesel engines; if it is a general-purpose part, it may be classified under other headings. Product Name: diesel engine cylinder head; Use: used for marine compression-ignition diesel engines; Material: cast iron; Brand: MAN; Model: L28/32; Applicable Engine Type: compression-ignition (diesel); Whether General-Purpose Part: dedicated part. Mistakenly classifying spark-ignition engine parts under 840999; they should be classified under 840991. Mistakenly classifying electrical parts used for diesel engines (such as starters) under 840999; they should be classified under Chapter 85. Declaring general mechanical parts (such as bearings) as dedicated diesel engine parts, resulting in incorrect classification.
Product Name
The specific name of the declared commodity, which should accurately reflect the function of the part, such as "diesel engine cylinder head", "diesel engine injector nozzle", etc.
⚠️ Writing only "engine parts" is too general; the specific part name should be provided.
Use
Explain what kind of machine the part is suitable for, such as "used for marine diesel engines", "used for generator set diesel engines", etc.
⚠️ Failure to indicate the use, or a use description unrelated to diesel engines.
Material
The main material of the declared part, such as cast iron, aluminum alloy, alloy steel, etc., which affects classification and customs valuation.
⚠️ Inaccurate material entry, such as mistakenly writing alloy steel as stainless steel.
Brand
Fill in the manufacturer or brand name; if there is no brand, fill in "no brand".
⚠️ The brand is inconsistent with the actual product, or omitted, making identification impossible.
Model
The model or specification of the part, used to distinguish the specific part and facilitate customs inspection.
⚠️ Incorrect model entry or inconsistency with the actual goods.
Applicable Engine Type
Clearly state whether it is compression-ignition (diesel) or spark-ignition; only diesel engines can be classified under 840999.
⚠️ Mistakenly declaring gasoline engine parts as diesel engine parts.
Whether General-Purpose Part
Explain whether the part is dedicated to diesel engines; if it is a general-purpose part, it may be classified under other headings.
⚠️ Declaring general bearings, gears, etc. as dedicated parts.
Mistakenly classifying spark-ignition engine parts under 840999; they should be classified under 840991.
Mistakenly classifying electrical parts used for diesel engines (such as starters) under 840999; they should be classified under Chapter 85.
Declaring general mechanical parts (such as bearings) as dedicated diesel engine parts, resulting in incorrect classification.
🎯 Classification Logic
Core criteria for classification: First, confirm whether the part is specially designed or principally used for internal combustion engines. Second, distinguish the type of internal combustion engine: spark-ignition (gasoline engine) under 840991, compression-ignition (diesel engine) under 840999. Third, exclude parts already named under other headings, such as fuel pumps (8413), injectors (8413), and electrical components (Chapter 85). Finally, if the part is a general-purpose item, classify it according to material or use. Therefore, 840999 applies to parts that are dedicated to diesel engines, non-electrical, and not named under other headings. 840991 Spark-ignition engine parts: Used for spark-ignition internal combustion engines such as gasoline engines, whereas 840999 is used for compression-ignition internal combustion engines such as diesel engines. 841330 Fuel pump: Fuel pumps are classified under 8413 regardless of the engine in which they are used, not under 8409. 851140 Starter: Starters are electrical devices classified under Chapter 85; even if dedicated to diesel engines, they are not classified under 8409. 848310 Drive shaft: If a drive shaft is a general mechanical transmission component, it is classified under 8483, not as a dedicated engine part. 732690 Other articles of iron or steel: If the part is a general iron or steel article without dedicated characteristics, it is classified under Chapter 73 according to material. Is it dedicated to diesel engines? Is it an electrical component? Is it already named under another heading? Is it a general mechanical part? Are the material and function consistent with the declaration?
Basis
Core criteria for classification: First, confirm whether the part is specially designed or principally used for internal combustion engines. Second, distinguish the type of internal combustion engine: spark-ignition (gasoline engine) under 840991, compression-ignition (diesel engine) under 840999. Third, exclude parts already named under other headings, such as fuel pumps (8413), injectors (8413), and electrical components (Chapter 85). Finally, if the part is a general-purpose item, classify it according to material or use. Therefore, 840999 applies to parts that are dedicated to diesel engines, non-electrical, and not named under other headings.
Confused Codes：
840991 - Spark-ignition engine parts
Used for spark-ignition internal combustion engines such as gasoline engines, whereas 840999 is used for compression-ignition internal combustion engines such as diesel engines.
841330 - Fuel pump
Fuel pumps are classified under 8413 regardless of the engine in which they are used, not under 8409.
851140 - Starter
Starters are electrical devices classified under Chapter 85; even if dedicated to diesel engines, they are not classified under 8409.
848310 - Drive shaft
If a drive shaft is a general mechanical transmission component, it is classified under 8483, not as a dedicated engine part.
732690 - Other articles of iron or steel
If the part is a general iron or steel article without dedicated characteristics, it is classified under Chapter 73 according to material.
Self-Check：
✓ Is it dedicated to diesel engines?
✓ Is it an electrical component?
✓ Is it already named under another heading?
✓ Is it a general mechanical part?
✓ Are the material and function consistent with the declaration?
❓ FAQ
Are all diesel engine parts classified under 840999? No. Only parts specially designed or principally used for compression-ignition internal combustion engines (diesel engines) are classified under 840999. However, if the part is already named under another heading (such as fuel pumps under 8413 or electrical components under Chapter 85), it is not classified under 840999. How do you distinguish between 840991 and 840999? 840991 is used for parts of spark-ignition internal combustion engines (such as gasoline engines), and 840999 is used for parts of other internal combustion engines (such as diesel engines). The key is the engine type: spark-ignition or compression-ignition. Under which code are diesel engine injectors classified? Injectors are usually classified under 8413 (pumps, liquid elevators, etc.) because their function is to inject fuel and they belong to pump-type devices, rather than being engine parts under 8409. Are turbochargers used for diesel engines classified under 840999? Turbochargers are generally classified under 8414 (air pumps or vacuum pumps, gas compressors, etc.) because they belong to the compressor category, rather than being dedicated engine parts. What elements are required to declare 840999? Product name, use, material, brand, model, applicable engine type (must be compression-ignition), and whether it is a general-purpose part are required. Ensure the information is accurate to avoid classification errors. How can the tariff rate for 840999 be checked? Tariff rates may change. It is recommended to check the latest rates through the official website of the General Administration of Customs, China International Trade Single Window, or by consulting a customs broker. Different rules of origin may apply to different agreement rates. If a diesel engine part is a general-purpose item, how should it be classified? If the part is a general mechanical item (such as a bearing or gear), it should be classified under the corresponding heading according to its material or function, such as bearings under 8482 and gears under 8483, rather than 840999. What is the relationship between 840999 and other subheadings under 8409? Under 8409 there are also 840910 (aircraft engine parts) and 840991 (spark-ignition engine parts). 840999 is a residual subheading used for internal combustion engine parts other than aircraft and spark-ignition, mainly diesel engine parts.
Q: Are all diesel engine parts classified under 840999?
A: No. Only parts specially designed or principally used for compression-ignition internal combustion engines (diesel engines) are classified under 840999. However, if the part is already named under another heading (such as fuel pumps under 8413 or electrical components under Chapter 85), it is not classified under 840999.
Q: How do you distinguish between 840991 and 840999?
A: 840991 is used for parts of spark-ignition internal combustion engines (such as gasoline engines), and 840999 is used for parts of other internal combustion engines (such as diesel engines). The key is the engine type: spark-ignition or compression-ignition.
Q: Under which code are diesel engine injectors classified?
A: Injectors are usually classified under 8413 (pumps, liquid elevators, etc.) because their function is to inject fuel and they belong to pump-type devices, rather than being engine parts under 8409.
Q: Are turbochargers used for diesel engines classified under 840999?
A: Turbochargers are generally classified under 8414 (air pumps or vacuum pumps, gas compressors, etc.) because they belong to the compressor category, rather than being dedicated engine parts.
Q: What elements are required to declare 840999?
A: Product name, use, material, brand, model, applicable engine type (must be compression-ignition), and whether it is a general-purpose part are required. Ensure the information is accurate to avoid classification errors.
Q: How can the tariff rate for 840999 be checked?
A: Tariff rates may change. It is recommended to check the latest rates through the official website of the General Administration of Customs, China International Trade Single Window, or by consulting a customs broker. Different rules of origin may apply to different agreement rates.
Q: If a diesel engine part is a general-purpose item, how should it be classified?
A: If the part is a general mechanical item (such as a bearing or gear), it should be classified under the corresponding heading according to its material or function, such as bearings under 8482 and gears under 8483, rather than 840999.
Q: What is the relationship between 840999 and other subheadings under 8409?
A: Under 8409 there are also 840910 (aircraft engine parts) and 840991 (spark-ignition engine parts). 840999 is a residual subheading used for internal combustion engine parts other than aircraft and spark-ignition, mainly diesel engine parts.
⚠️ Disclaimer: HS code classification, declaration elements, tariff rates and regulatory conditions on this page are for reference only and do not constitute legal advice on customs classification. Tariff rates and regulations are subject to change; the latest announcements from the General Administration of Customs and on-site determinations shall prevail. Please consult professional customs brokers or customs authorities before import/export.