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THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH (making helical grooves by turning B23B 5/48, by milling B23C 3/32, by forging, pressing, or hammering B21K 1/56, by grinding B24B 19/02; arrangements for copying or controlling B23Q; thread forming by corrugating tubes B21D 15/04, by rolling B21H 3/02)
Definition statement
This subclass/group covers:

Thread cutting by chip removal.

Production of threads with no removal of chips by means of tools similar in form and manner of use to thread cutting tools.

Working of screws, bolt heads and nuts in conjunction with thread cutting.

References relevant to classification in this subclass
This subclass/group does not cover:
Thread forming by corrugating tubes
Making threaded elements by forging/hammering
Making nuts by forging or hammering
Making screwthreads by rolling
Turning helical grooves
Turning tools for threading
Milling helical grooves
Making gears (inc wormwheels)
Making milling cutters for threading
Making threading tools
Multi stage processes involving threading and also other operations classed in B23B, B23C, B23D, B23F, making particular items
Details of machine tools and accessories not related to the operation being performed including:
- evacuation of swarf,
- guarding & protective coverings
- conveying workpiece into and from machine
- tool changing
- measuring or sensing
Adaptive control and/or computer controls for turning, boring or drilling processes
Grinding helicoidal grooves
Fasteners per se
Special rules of classification within this subclass

Classification in this subclass is according to a literal interpretation of the group and subgroup headings.

Indexing Codes from the 200 series (i.e ICO codes from the following groups: B23G 2200/00 to B23G 2200/50, B23G 2210/00 to B23G 2210/48, B23G 2225/00 to B23G 2225/60 and B23G 2240/00 to B23G 2240/60) should be added to documents at every possible opportunity for deep indexing.

A ECLA mirror image ICO code scheme (i.e. B23G 1/00 to B23G 11/00) has recently been created. However, this scheme should NOT be used for classification of new documents.

At the end of this document drawings have been provided, which give examples of the items classified in the most widely used subgroups. The example drawings have each been taken from a document classified within the subgroup, for which the example is provided.

The term "similar in form and in manner of use to thread cutting tools" of B23G 7/00 should be strictly interpreted. The forming tool being used should bear a very close resemblance to known cutting tools. Examples of such tools are forming taps (roll taps), and forming tools resembling milling cutters and used with a helical feed.

The term "in conjunction with thread cutting" in the title of group B23G 9/00 should be interpreted in a very strict and limited manner. Documents should only be classified in B23G 9/00 if the content refers to the mechanical working of the screw, bolt or nut. For example the coating of screwthreads should be classified either according to the fastener per se or according to the process being used.

B23G 11/00 refers to feeding or discharging mechanisms in so far as they are specifically destined for thread cutting machines. B23Q 7/00 is used for feeding or discharging mechanisms in general.



None of the drawings is original and no copyright is claimed.

The majority of the drawings are each taken from a document classified in the group or subgroup, to which the example refers.

Thread cutting; Automatic machines specially designed therefor
Arrangements or accessories for enabling machine tools not specially designed only for thread cutting to be used for this purpose, e.g. arrangements for reversing the working spindle
Thread-cutting tools; Die-heads
Forming thread by means of tools similar both in form and in manner of use to thread-cutting tools, but without removing any material (features of machines or devices not specially adapted to the particular mode of forming the thread B23G 1/00)
Working screws, bolt heads, or nuts in conjunction with thread cutting, e.g. slotting screw heads or shanks, removing burrs from screw heads or shanks; Finishing, e.g. polishing, any screw-thread
Feeding or discharging mechanisms combined with, or arranged in, or specially adapted for use in connection with, thread-cutting machines (for machines tools in general B23Q)
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Last Modified: 10/11/2013