TNGN 220412 Insert

TNGN 220412 decoded: shape, clearance, tolerance class, mounting, inscribed circle, thickness and corner radius, with the ANSI equivalent (TNGN 433).

Data verified 2026-09-29 · based on ISO 1832:2017

Quick Answer

TNGN 220412 is an ISO 1832 turning insert. It is a 60° triangular negative insert with a 0° clearance, an inscribed circle of 12.7 mm (0.5000 in), a thickness of 4.76 mm and a corner radius of 1.2 mm — 6 usable corners.

Decoding TNGN 220412

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 TNGN 220412 left to right:

Pos.	Symbol	Meaning	Value for TNGN 220412
1	`T`	Shape	60° triangular — 60° nose angle, 6 corners per side
2	`N`	Clearance angle	0° — negative insert (double-sided)
3	`G`	Tolerance class	IC ±0.025 mm, edge position ±0.025 mm, thickness ±0.13 mm
4	`N`	Mounting and chip breaker	Mounting style 1, chip breaker none
5	`22`	Size (cutting edge ≈)	Inscribed circle 12.7 mm (0.5000 in)
6	`04`	Thickness	4.76 mm (0.1874 in)
7	`12`	Corner radius	1.2 mm (0.0472 in)

Dimensions and tolerances

Dimension	Where it comes from	Value
Designation	ISO 1832	TNGN 220412
ANSI equivalent	ANSI B212.12	TNGN 433
Shape	Position 1 — T	60° triangular, 60° nose angle
Usable corners	Position 1 and 2 combined	6 (negative)
Clearance angle	Position 2 — N	0°
Inscribed circle, d	Position 5	12.7 mm / 0.5000 in
Thickness, s	Position 6	4.76 mm / 0.1874 in
Corner radius, r	Position 7	1.2 mm / 0.0472 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

Tolerances are the ISO 1832 limits for tolerance class G. A premium manufacturer may hold tighter limits than the standard requires, but is unlikely to state this formally — so a delivered insert can be better than the table, never worse.

What this insert is for

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

No fixing hole, no chip breaker.

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

Value Sources

Each data column on this page is tied to the source it came from. The numbers in square brackets correspond to the table headers above.

#	Source	Type	Revision / method
[1]	ANSI B212.12 — Indexable inserts, identification system	standard	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 13399 — Cutting tool data representation and exchange	standard	ISO 13399-1:2006
[4]	ISO 1832 — Indexable inserts for cutting tools, designation	standard	ISO 1832:2017 — source
[5]	ISO 513 — Classification and application of hard cutting materials	standard	ISO 513:2012

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
ISO 13399 — Cutting tool data representation and exchange	ISO 13399-1:2006	the ISO 13399 codes given for each dimension
ANSI B212.12 — Indexable inserts, identification system	ANSI B212.12-1991 (R2017)	the ANSI inch designation and its size, thickness and radius symbols

Cross-checked against:

Symbol tables checked against the ISO 1832 designation system
Every millimetre value converted to inches at build time and checked against the ANSI symbol relationship
The size symbol verified against the cutting-edge-length approximation for each shape
Decoded designations spot-checked against manufacturer catalogue listings

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. The values on this page are compiled from the published standards and cross-checked sources listed above. Where values are derived, the derivation is stated. 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

Every value on this page is traceable to the sources listed above. If you use the data in a document, paper or report, cite it as:

Plain text

Engineering Reference. "TNGN 220412 — ISO Turning Insert." https://refmanual.com/inserts/tngn-220412/ (accessed 2026-09-29). Data from ISO 1832 — Indexable inserts for cutting tools, designation, ISO 1832:2017.

BibTeX

@misc{tngn-220412,
  title        = {TNGN 220412 — ISO Turning Insert},
  author       = {{Engineering Reference}},
  howpublished = {\url{https://refmanual.com/inserts/tngn-220412/}},
  note         = {Accessed: 2026-09-29},
  source       = {ISO 1832 — Indexable inserts for cutting tools, designation, ISO 1832:2017}
}

RIS (EndNote, Zotero, Mendeley)

TY  - ELEC
TI  - TNGN 220412 — ISO Turning Insert
AU  - Engineering Reference
PB  - Engineering Reference
UR  - https://refmanual.com/inserts/tngn-220412/
PY  - 2026
DA  - 2026-09-29
N1  - Source: ISO 1832 — Indexable inserts for cutting tools, designation, ISO 1832:2017
ER  -

Each row in the tables above also has a permanent link — hover a row and use the # link to cite a single value rather than the whole page.