Turning inserts are named by one international code (ISO 1832). The first seven positions mean the same for every manufacturer; positions 8 and 9 are added when needed; after them each manufacturer adds its own chipbreaker and grade. The tables below are the ones Canela prints in its turning inserts catalog, so every value can be checked on the page.
Take CNMG120408MC-TN15, the example Canela itself prints on page A23:
1Shape · C
The first letter is the shape of the insert and the angle of its corner. A wide corner (R, S, C) is strong and takes heavy cuts; a narrow one (D, V) reaches into profiles. In the example, C: rhombic 80°.
- V
- Rhombic 35°
- D
- Rhombic 55°
- E
- Rhombic 75°
- C
- Rhombic 80°
- M
- Rhombic 86°
- K
- Parallelogram 55°
- B
- Parallelogram 82°
- A
- Parallelogram 85°
- L
- Rectangular 90°
- P
- Pentagonal 108°
- H
- Hexagonal 120°
- O
- Octagonal 135°
- R
- Round
- S
- Square 90°
- T
- Triangular 60°
- W
- Trigon 80°
- X
- Special design
Source: Canela turning inserts catalog, page A24.
2Clearance angle · N
The second letter is the clearance angle under the cutting edge. N is 0°: a negative insert, which is often double-sided. A letter with an angle (B, C, P) is a positive insert, used on one side. In the example, N: 0°.
- A
- 3°
- B
- 5°
- C
- 7°
- D
- 15°
- E
- 20°
- F
- 25°
- G
- 30°
- N
- 0°
- P
- 11°
Source: Canela turning inserts catalog, page A24.
3Tolerance class · M
The third letter is how closely the insert is made: the corner height m, the inscribed circle d and the thickness s. M is the usual class of a pressed insert; G is ground and tighter. In the example, M: m ±0.08–0.20 · d ±0.05–0.15 · s ±0.13.
- A
- m ±0.005 · d ±0.025 · s ±0.025
- F
- m ±0.005 · d ±0.013 · s ±0.025
- C
- m ±0.013 · d ±0.025 · s ±0.025
- H
- m ±0.013 · d ±0.013 · s ±0.025
- E
- m ±0.025 · d ±0.025 · s ±0.025
- G
- m ±0.025 · d ±0.025 · s ±0.013
- J
- m ±0.005 · d ±0.05–0.15 · s ±0.025
- K
- m ±0.013 · d ±0.05–0.15 · s ±0.025
- L
- m ±0.025 · d ±0.05–0.15 · s ±0.025
- M
- m ±0.08–0.20 · d ±0.05–0.15 · s ±0.13
- N
- m ±0.08–0.20 · d ±0.05–0.15 · s ±0.025
- U
- m ±0.13–0.38 · d ±0.08–0.25 · s ±0.13
Source: Canela turning inserts catalog, page A24.
4Hole and chipbreaker · G
The fourth letter says whether the insert has a fixing hole and a chipbreaker, and on which sides. In the example, G: cylindrical hole, double-sided chipbreaker.
- N
- No hole, no chipbreaker
- R
- No hole, one-sided chipbreaker
- F
- No hole, double-sided chipbreaker
- A
- Cylindrical hole, no chipbreaker
- M
- Cylindrical hole, one-sided chipbreaker
- G
- Cylindrical hole, double-sided chipbreaker
- W
- Hole with one countersink (40–60°), no chipbreaker
- T
- Hole with one countersink (40–60°), one-sided chipbreaker
- Q
- Hole with double countersink (40–60°), no chipbreaker
- U
- Hole with double countersink (40–60°), double-sided chipbreaker
- B
- Hole with one countersink (70–90°), no chipbreaker
- H
- Hole with one countersink (70–90°), one-sided chipbreaker
- C
- Hole with double countersink (70–90°), no chipbreaker
- J
- Hole with double countersink (70–90°), double-sided chipbreaker
- X
- Special design
Source: Canela turning inserts catalog, page A24.
5Size · 12
Two digits give the size: the length of the cutting edge in whole millimetres. The table on the catalog page gives the inscribed circle for each shape; for a C insert it reads like this. In the example, 12: inscribed circle 12.70 mm.
- 03
- Inscribed circle 3.97 mm
- 04
- Inscribed circle 4.76 mm
- 05
- Inscribed circle 5.56 mm
- 06
- Inscribed circle 6.35 mm
- 08
- Inscribed circle 7.94 mm
- 09
- Inscribed circle 9.52 mm
- 12
- Inscribed circle 12.70 mm
- 16
- Inscribed circle 15.87 mm
- 19
- Inscribed circle 19.00 mm
- 22
- Inscribed circle 22.22 mm
- 25
- Inscribed circle 25.40 mm
- 32
- Inscribed circle 31.75 mm
Source: Canela turning inserts catalog, page A25.
6Thickness · 04
Two digits give the thickness of the insert. In the example, 04: 4.76 mm.
- 01
- 1.59 mm
- 02
- 2.38 mm
- 03
- 3.18 mm
- T3
- 3.97 mm
- 04
- 4.76 mm
- 05
- 5.56 mm
- 06
- 6.35 mm
- 07
- 7.94 mm
- 09
- 9.52 mm
Source: Canela turning inserts catalog, page A25.
7Corner radius · 08
Two digits give the corner radius in tenths of a millimetre. A larger radius makes the corner stronger and the surface smoother at the same feed; a smaller one presses less on the part. In the example, 08: 0.8 mm.
- 00
- 0.0 mm
- M0
- 0.0 mm
- 02
- 0.2 mm
- 04
- 0.4 mm
- 08
- 0.8 mm
- 12
- 1.2 mm
- 16
- 1.6 mm
- 20
- 2.0 mm
- 24
- 2.4 mm
- 32
- 3.2 mm
Source: Canela turning inserts catalog, page A25.
8Cutting edge condition
Positions 8 and 9 appear only when the manufacturer needs them. The eighth is how the cutting edge is prepared.
- F
- Sharp
- E
- Honed
- T
- Chamfered
- S
- Chamfered and honed
- K
- Double-chamfered
- P
- Double-chamfered and honed
Source: Canela turning inserts catalog, page A25.
9Cutting direction
The ninth is the hand of the insert.
- R
- Right
- L
- Left
- N
- Neutral
Source: Canela turning inserts catalog, page A25.
10The manufacturer’s own symbols
After the ISO positions come the manufacturer’s own names. In the example, MC is Canela’s chipbreaker: general purpose on all types of steel and stainless steel. TN15 is the grade: CVD coated carbide; on the grade chart P10–P25, M10–M25, K05–K20, S05–S15.
Another manufacturer names its chipbreakers and grades differently, so the code alone does not make two inserts interchangeable: compare the geometry, the grade and the cutting data on the catalog pages.
Read any Canela code position by position