TCGT 090204 Insert

TCGT 090204 decoded: shape, clearance, tolerance class, mounting, inscribed circle, thickness and corner radius, with the ANSI equivalent (TCGT 21.51).

Page last changed 2026-10-19 · based on ISO 1832:2017

Quick Answer

TCGT 090204 is an ISO 1832 turning insert. It is a 60° triangular positive insert with a 7° clearance, an inscribed circle of 5.56 mm (0.2189 in), a thickness of 2.38 mm and a corner radius of 0.4 mm — 3 usable corners.

Decoding TCGT 090204

An ISO 1832 designation has 13 possible positions, of which the first seven are mandatory. The first four form the design group and describe the insert's outline; the last three form the dimensions group and describe its size. Reading TCGT 090204 left to right:

Pos.	Symbol	Meaning	Value for TCGT 090204
1	`T`	Shape	60° triangular — 60° nose angle, 3 corners per side
2	`C`	Clearance angle	7° — positive insert (single-sided)
3	`G`	Tolerance class	IC ±0.025 mm, edge position ±0.025 mm, thickness ±0.13 mm
4	`T`	Mounting and chip breaker	Mounting style 3, chip breaker one face
5	`09`	Size (cutting edge ≈)	Inscribed circle 5.56 mm (0.2189 in)
6	`02`	Thickness	2.38 mm (0.0937 in)
7	`04`	Corner radius	0.4 mm (0.0157 in)

Dimensions and tolerances

Dimension	Where it comes from	Value
Designation	ISO 1832	TCGT 090204
ANSI equivalent	ANSI B212.12	TCGT 21.51
Shape	Position 1 — T	60° triangular, 60° nose angle
Usable corners	Position 1 and 2 combined	3 (positive)
Clearance angle	Position 2 — C	7°
Inscribed circle, d	Position 5	5.56 mm / 0.2189 in
Thickness, s	Position 6	2.38 mm / 0.0937 in
Corner radius, r	Position 7	0.4 mm / 0.0157 in
Tolerance on d	Class G	±0.025 mm
Tolerance on edge position, m	Class G	±0.025 mm
Tolerance on thickness, s	Class G	±0.13 mm

These are reference tolerance values associated with the designation. They are not inspection results or a guarantee for a delivered insert. Confirm the applicable catalogue, purchase specification and inspection requirements.

What this insert is for

Compact for its edge length, with three corners. Limited profiling ability and a relatively weak edge.

Countersunk hole, chip breaker on one face.

Ground inserts — tighter IC and edge position, used where indexing repeatability matters.

Value Sources

References and calculation methods used for this page are listed below. Numbered markers connect table columns where present. A reference listing does not itself establish that every value has been independently checked.

#	Source	Type	Revision / method
[1]	ANSI B212.12 — Indexable inserts, identification system	reference	ANSI B212.12-1991 (R2017)
[2]	Field values computed from the designation	derived	Every field on this page is decoded from the designation letters and digits using the ISO 1832 symbol tables. Nothing is looked up from a catalogue, and the inch values are computed as millimetres ÷ 25.4.
[3]	ISO 1832 — Indexable inserts for cutting tools, designation	reference	ISO 1832:2017 — source

Data Sources

Standard	Revision	What it covers on this page
ISO 1832 — Indexable inserts for cutting tools, designation	ISO 1832:2017	all seven designation positions and their symbol tables
ANSI B212.12 — Indexable inserts, identification system	ANSI B212.12-1991 (R2017)	the ANSI inch designation and its size, thickness and radius symbols

Verification scope

No page-specific independent source review is recorded here. The listed references and formulas explain the basis of the compilation; automated consistency checks do not verify the original sources or establish product conformity.

Derived values — the following values on this page are calculated, not taken directly from the standard:

Value	How it is derived
All fields	Decoded from the designation by the ISO 1832 symbol tables in the page generator.

Only positions 1 to 7 are decoded. Positions 8 to 13 describe edge preparation, wiper geometry, cutting direction and other features, and are manufacturer-specific. The ISO 1832 tables define the envelope; the chip breaker geometry behind position 4 is proprietary and is not described by the standard.

Accuracy and use. Use the source notes and recorded verification scope above to assess each value. Calculated values follow the stated derivations; compilation values may lack a confirmed original document or product condition. No warranty, express or implied, is made as to the accuracy or completeness of this information, and no liability is accepted for any loss or damage arising from its use. Engineering reference data is provided for guidance in preliminary work — before a value is used for design, fabrication or acceptance testing, verify it against the current revision of the governing standard and against your own inspection. The user assumes all risk and responsibility in connection with the use of this information.

Cite This Page

Read the source notes, calculation methods and verification scope above before reusing a value. To cite this page:

Plain text

Engineering Reference. "TCGT 090204 — ISO Turning Insert." https://refmanual.com/inserts/tcgt-090204/ (accessed 2026-10-19). Data from ISO 1832 — Indexable inserts for cutting tools, designation, ISO 1832:2017.

BibTeX

@misc{tcgt-090204,
  title        = {TCGT 090204 — ISO Turning Insert},
  author       = {{Engineering Reference}},
  howpublished = {\url{https://refmanual.com/inserts/tcgt-090204/}},
  note         = {Accessed: 2026-10-19},
  source       = {ISO 1832 — Indexable inserts for cutting tools, designation, ISO 1832:2017}
}

RIS (EndNote, Zotero, Mendeley)

TY  - ELEC
TI  - TCGT 090204 — ISO Turning Insert
AU  - Engineering Reference
PB  - Engineering Reference
UR  - https://refmanual.com/inserts/tcgt-090204/
PY  - 2026
DA  - 2026-10-19
N1  - Source: ISO 1832 — Indexable inserts for cutting tools, designation, ISO 1832:2017
ER  -