What’s the difference between “part” and “accessory” under HS code?
There is no clear definition in HS Tariff or even Explanatory note.

Instead, we can see the definition in customs ruling case of “sewing machine”.
The issue of this ruling is that whether Sewing Machine Light is “part” or “ lamp” as an accessory.

The following HS codes are under consideration:

8452.90: Sewing machines, other than book-sewing machines of heading 8440; furniture, bases and covers specially designed for sewing machines; sewing machine needles; parts thereof:

9405.40: Lamps and lighting fittings including searchlights and spotlights and parts thereof, not elsewhere specified or included; illuminated signs, illuminated nameplates and the like, having a permanently fixed light source, and parts thereof not elsewhere specified or included:

Source:European Union Website

Part

“part” of an article is something necessary to the completion of that article. It is an integral, constituent, or component part, without which the article to which it is to be joined, could not function as such article. 

Source: United States v. Willoughby Camera Stores, Inc., 21 C.C.P.A. 322 (1933)

Accessory

“accessory”  is not necessary to the functioning of the sewing machine but serves the subordinate purpose of illuminating the stitching area. Merchandise used in conjunction with an item in a subordinate role to the function of that item has been described as an accessory, and not as a part,

Source: the Court of International Trade. See, Rollerblade, Inc. v. United States, 116 F. Supp. 2d 1247, 1252 (Ct. Int’l Trade, 2000).

Conclusion

Sewing machine light is classified as other electric lamps and lighting fittings HS:9405.
Since the sewing machine will function even if the lamp is subsequently removed and it serves the subordinate purpose of illuminating the stitching area, it can not be classified as a part of a sewing machine.

Here quote from customs ruling case of “sewing machine”

The sewing machine light illuminates the sewing area in the same manner as any overhead or desk lamp. Although dedicated for use with a sewing machine, the sewing machine will function even if the lamp is subsequently removed. Furthermore, the instant merchandise is advertised as an “accessory” and is not necessary to the functioning of the sewing machine but serves the subordinate purpose of illuminating the stitching area. Merchandise used in conjunction with an item in a subordinate role to the function of that item has been described as an accessory, and not as a part, by the Court of International Trade. See, Rollerblade, Inc. v. United States, 116 F. Supp. 2d 1247, 1252 (Ct. Int’l Trade, 2000).

What are the Definitions of “parts of general use”?
According to Explanatory Note Section XV note 2, “parts of general use” defined as below.

2.Throughout the Nomenclature, the expression “parts of general use” means：

（a） Articles of heading 73.07,73.12,73.15,73.17 or 73.18 and similar articles of other
base metals;

（b） Springs and leaves for springs、of base metal、other than clock or watch springs（heading 91.14）; and

（c） Articles of headings 83.01、83.02、83.08、83.10 and frames and mirrors、of base metal、of heading 83.06。

In Chapters 73 to 76 and 78 to 82 (but not in heading 73.15) references to parts of goods
do not include references to parts of general use as defined above.
Subject to the preceding paragraph and to Note 1 to Chapter 83, the articles of Chapter
82 or 83 are excluded from Chapters 72 to 76 and 78 to 81.

In this definition, many HS codes are scattered throughout the definition.
Hence still unclear what “parts of general use” mean.

Below are an image list of “parts of general use” for each HS code defined in Explanatory Note Section XV note 2.

HS7307: Tube or pipe fittings

(for example, couplings, elbows, sleeves), of iron or steel:

HS7312: Stranded wire, ropes,

cables, plaited bands, slings and the like, of iron or steel, not electrically insulated:

HS7315: Chain and parts thereof, of iron or steel:

HS7317: Nails, tacks, drawing pins, corrugated nails, staples

HS7318: Screws, bolts, nuts, coach screws,

screw hooks, rivets, cotters, cotter pins, washers (including spring washers) and similar articles, of iron or steel

HS: 7318.21: Spring washers and other lock washers

HS8301: Padlocks and locks

HS8302:Base metal mountings, fittings and similar articles

suitable for furniture, doors, staircases, windows, blinds, coachwork, saddlery, trunks, chests, caskets or the like; base metal hat racks, hat-pegs, brackets and similar fixtures; castors with mountings of base metal; automatic door closers of base metal; and base metal parts thereof:

HS8308: Clasps, frames with clasps,

buckles, buckle-clasps, hooks, eyes, eyelets and the like, of base metal, of a kind used for clothing or clothing accessories, footwear, jewelry, wrist watches, books, awnings, leather goods, travel goods or saddlery or for other made up articles; tubular or bifurcated rivets, of base metal; beads and spangles, of base metal:

HS8310: Sign plates, name plates,

address plates and similar plates, numbers, letters and other symbols, and parts thereof, of base metal, excluding those of heading 9405

HS:8306 Bells, gongs and the like,

nonelectric, of base metal; statuettes and other ornaments, of base metal; photograph, picture or similar frames, of base metal; mirrors of base metal; and base metal parts thereof:

When it comes to classifying automotive parts made of plastic,
one of the options is HS:392630 (Fittings for furniture, coachwork, or the like:)

I wonder why HS tariff used the terms of “coachwork”??
It should be “automotive”??

And also many people may wonder what kind of items are classified as “Fittings for Coachwork”?
So I retrieved items which are classified as “Fittings for Coachwork”(HS:3926.30)
from many customs ruling database.

Below is the list of the items classified as “Fittings for Coachwork”(HS:3926.30)

“Fittings for Coachwork”(HS:3926.30)

door handle
Czech Customs:CZBTI37/086941/2018-580000-04/01

cable guide
German customs:DE239/17-1

cable guide
German customs:DE686/17-1

cover  mounted behind the interior trim of motor vehicle door
German customs:DE966/17-1

panel for window frames
German customs:DE4899/16-1

belt deflector
German customs:DE4949/17-1

cover assembly hole are directly and permanently mounted on motor vehicles behind the inner panel on the body of the left door
German customs:DE8666/17-1

entry bar made of molded plastic
German customs:DE14779/16-1

mounting bracket used to hold control units
German customs:DEBTI1836/18-1

The approximately 32.4 x 24.4 x 10.4 cm shaped product is essentially eleven Recesses for relay socket and plug couplings and a large main compartment for a control unit provided
German customs:DEBTI3532/18-1

door handle
German customs:DEBTI13185/18-1

universal mount for example, Mobile phones or iPods with two self-locking clamping devices
German customs:DEHH/15/09-1

door handle
German customs:DEHH/1118/05-1

Plates and emblems for tourist cars
spain customs:ESBTI2017SOL0000000000749

automotive plastic wheel attachment
French customs:FR-E4-2006-002796

Chrome-plated plastic edging for the power window block mounted on the car door next to the driver
Latvia customs:LVBTI2019-91

Interior door handle
Slovakia customs:SK13409/09/5219/28

Plastic but not “Fittings for Coachwork”(goes to 8708)

Even though the items below are made of plastic, they are essential parts of automobiles and satisfy all three of the following conditions:(Section XVII GENERAL(III))

(a) They must not be excluded by the terms of Note 2 to this Section
(b) They must be suitable for use solely or principally with the articles of Chapters 86 to
88
(c) They must not be more specifically included elsewhere in the Nomenclature

Therefore they are not classified as HS:3926.30

The plastic blower for cars
Slovakia customs:SK12536/16/02

Parts of a steering column
ドイツ税関(DE):DE892/17-1

CONSOLE
United Kingdom customs:GB501958157

Glove box
German customs:DE4894-16-1

Reflector for motor vehicles
Belgium customs:BED.T.251.513

DOOR COMPARTMENT (ASHTRAY)
Italy customs:ITBTIIT-2017-0430M-314100

Retrieved from:European Union Website

“Fittings for Coachwork” is a vague term. I looked for the definition of it but could not find it.

Here is just my opinion to differ from them.
plastic parts for automotive which work directly for the automotive mechanism goes to 8708.
On the contrary plastic parts for automotive which works as Accessories, like connecting, attach, fix something to the place, etc goes to 3926.30(fittings for coachwork)

Since there is no clear definition for it, I determine them by items picture obtaining from the customs ruling database.

Please refer to the above pictures to see the difference between auto parts made of plastic 3926 and 8708.

Hinges are usually classified as HS:8302.10.
But what if that hinge is used solely for Automotive parts?
You might think there is also the possibility of that being classified as Auto parts HS:8708

In order to make a clear line between HS:8302 and HS:8708, you need to understand two definitions.

1.What is excluded from heading 8708
2.Definitions of “general use parts”

What is excluded from heading 8708

According to CBP “Vehicles, Parts and Accessories Under the HTSUS”.(Section XVII GENERAL(III))
In order for motor vehicle parts or accessories to be classifiable under heading 8708, they must satisfy all three of the following conditions: otherwise, they are excluded from heading 8708.

(a) They must not be excluded by the terms of Note 2 to this Section
(see paragraph (A) below).

(b) They must be suitable for use solely or principally with the articles of Chapters 86 to
88 (see paragraph (B) below).

(c) They must not be more specifically included elsewhere in the Nomenclature (see
paragraph (C) below).

Above definitions (b) and (c) are understandable but (a) is not,so we need to refer Section XVII note2

Section XVII note2

The expressions “parts” and “parts and accessories” do not apply to the following articles、whether or not they are identifiable as for the goods of this Section：

（a） Joints、washers or the like of any material（classified according to their constituent material or in heading 84.84）or other articles of vulcanised rubber other than hard rubber（heading 40.16）;

（b） Parts of general use、as defined in Note 2 to Section XV、of base metal（Section XV）、or similar goods of plastics（Chapter 39）;

In this note, parts of general use are excluded from HS:8708 so what’s the definition of parts of general use? we need to refer to Note 2 to Section XV.

Definitions of “parts of general use”

Note 2 to Section XV state.

2.Throughout the Nomenclature, the expression “parts of general use” means：

（a） Articles of heading 73.07,73.12,73.15,73.17 or 73.18 and similar articles of other base metals;

（b） Springs and leaves for springs、of base metal、other than clock or watch springs（heading 91.14）; and

（c） Articles of headings 83.01、83.02、83.08、83.10 and frames and mirrors、of base metal、of heading 83.06。

With the above definitions, we can see that HS:8302 is excluded from HS:8708.

And also Explanately note states that “hinges for automobiles” belong to HS:8302.

Automotive hinge’s customs rulings

Item image
Issued Country	Spain
Reference	ES-2012-000558-0636/10
Issuing date	2012-10-29
Item name	hinge
Classified HS code	8302.10
Details & Customs Opinion	Article commonly used consistently in the male (fixed) a hinge made of galvanized steel. Has a width of 31mm and ends in a shaft with a diameter of 15mm. Used in automotive vehicles (trailers) to support the side door of the trailer. GIR 1 and 6, Notes 2 and 3 of Section XV, Note 2 b) of Section XVII, Note 1 to Chapter 83 and the wording of CN codes 8302, 8302.10.00, 8302.10.00.90 TARIC code.

Item image
Issued Country	Spain
Reference	ES-2012-000581-0433/10
Issuing date	2012-10-29
Item name	hinge
Classified HS code	8302.10
Details & Customs Opinion	Article general purpose steel, consisting of the mobile part of a hinge, which is fixed in the door. It has a length of 215mm and a maximum width of 140mm. Shaped like a square and one end has a hole with a diameter of 13mm. Used in automotive vehicles (trailers) in the back door. GIR 1 and 6, Notes 2 and 3 of Section XV, Note 2 b) of Section XVII, Note 1 to Chapter 83 and the wording of CN codes 8302, 8302.10.00, 8302.10.00.90 TARIC code.

Source:European Union Website

Most of the cases bolts/nuts/screws are usually classified as 7318 or depending on the materials(ex.plastic screws HS3926.90) even though they are used as auto parts.

But the US tends to classify them as auto parts 8708 if they have a specific purpose rather than screwed into something.

There lies a thin line between HS7318 and HS 8708 it’s like a coin-toss game.
Here are US customs advanced ruling decision database called CROSS‘s result for the keyword of “screw”

You can see two separate decisions.

Here are Indian import statistics database with HScode, the result for the keyword of “screw automobile”

You can also see two separate decisions.

Of course, the best way to avoid misclassification is to apply the advance ruling to importing customs but the procedure is really complexed and time-consuming.

When it comes to importing “bolts/nuts/screws” for automobiles.
further consideration is needed.

1.Cleary define what that “bolts/nuts/screws” are used for.
If they are used something rather than screwed into something, You need to understand what they are used for. This is the most important thing.

2.Prepare authority of classification from Explanatory notes with item’s documents and submit it to the customs before the import examination started by an officer.
It’s important to submit them before being questioned by a customs officer.
the officer is like a child with pride.
Even if your claim is valid.once they doubt the classification they hardly withdraw what they said due to their pride. In order to avoid this situation, you should submit all the detailed and valid authority of classification before the import examination started.

3.Search as many customs rulings decision as possible to make a conviction of classification.

Here are the customs rulings decision database.

US customs “CROSS”

CROSS

EU taxation and customs union “BTI Consultation”

BTI Consultation