CNMG-GR – INNOT insert

CNMG-GR

80° negative insert for roughing steels, with GR chipbreaker and INNOT CVD grades.

ISO P
Roughing
CVD
★ IT8115 · IT8225

Request a quote

Technical data sheet PDFCutting data, sizes and grades

Want to try it first? Request a free tester

Fits on
Boring bars for internal turning95° external turning toolholders

Prices reserved for companiesLog in to your customer area to see your prices and request new ones in one click.
Sign in
Need technical advice? Talk to INNOT

(+39) 375 786 1361 Call · WhatsApp

INNOT grades

CVD, PVD and cermet for ISO P, M, K, S

Standard ISO designation

Compatible with the insert holders you use

Technical support

We help you choose grade and chipbreaker

Shipping in 24/48 h

For stock orders throughout Italy

Categories: ,

Description

ISO specifications

ISO RADIUS (RE) AVAILABLE GRADES CHIPBREAKER
CNMG1204 0.8 – 1.2 IT8105 – IT8115 – IT8125 – IT8225 GR
CNMG1606 0.8 – 1.2 – 1.6 IT8105 – IT8115 – IT8125 – IT8225 GR
CNMG1906 0.8 – 1.2 – 1.6 IT8105 – IT8115 – IT8125 – IT8225 GR

GR chipbreaker data sheet

Operation Roughing
ISO material P (non-alloy, alloy and tool steels)
Tolerance M
Features First choice for roughing ISO P materials. The chip-breaking land with a raised angle controls chip flow even at low depths of cut. A large rake angle and a wide chamfer ensure a sharp and strong cutting edge. The double groove improves chip evacuation and makes the insert versatile: suitable for roughing and semi-finishing under heavy loads.

Available INNOT grades

Grade ISO Coating Composition Application
IT8105 P CVD TiN + MT-TiCN + Al₂O₃ Turning of steel in stable conditions. High hot hardness, resistance to wear and plastic deformation.
IT8115 ★ P CVD TiN + MT-TiCN + Al₂O₃ Continuous and lightly interrupted cuts. Finishing and semi-finishing of carbon and alloy steels.
IT8125 P CVD TiN + MT-TiCN + Al₂O₃ Interrupted and continuous cuts on steel. The reinforced substrate limits plastic deformation at high temperature.
IT8225 ★ P CVD TiN + MT-TiCN + Al₂O₃ First-choice grade for steel, very versatile. Multilayer coating with excellent wear resistance and toughness.

★ Recommended grade for this chipbreaker. CVD = chemical vapour deposition coating. ISO P = steels.

Recommended cutting data

Printable cutting data tableAll the data on this page in an INNOT PDF to keep in the shop.Download PDF
External turning of steels (ISO P) – GR chipbreaker

Recommended cutting data by material and cutting condition (stable, average, difficult).

Material Condition Vc (m/min) by grade fn (mm/rev) ap (mm)
Structural steels ≤ 180 HB
(S235, C45…)		 Stable IT8115: 235 – 320
IT8125: 185 – 295
IT8225: 195 – 315		 0.25 – 0.60 2.00 – 7.00
Structural steels ≤ 180 HB
(S235, C45…)		 Average IT8115: 235 – 320
IT8125: 195 – 315
IT8225: 185 – 295		 0.25 – 0.55 2.00 – 7.00
Structural steels ≤ 180 HB
(S235, C45…)		 Difficult IT8115: 235 – 320
IT8125: 185 – 295
IT8225: 195 – 315		 0.25 – 0.50 2.00 – 7.00
Carbon and alloy steels 180 – 280 HB
(41Cr4, 42CrMo4…)		 Stable IT8115: 235 – 320
IT8125: 195 – 315
IT8225: 185 – 295		 0.25 – 0.60 2.00 – 7.00
Carbon and alloy steels 180 – 280 HB
(41Cr4, 42CrMo4…)		 Average IT8115: 235 – 320
IT8125: 195 – 315
IT8225: 185 – 295		 0.25 – 0.55 2.00 – 7.00
Carbon and alloy steels 180 – 280 HB
(41Cr4, 42CrMo4…)		 Difficult IT8115: 235 – 320
IT8125: 195 – 315
IT8225: 185 – 295		 0.25 – 0.50 2.00 – 7.00
Quenched and tempered steels ≥ 280 HB Stable IT8115: 225 – 360 0.25 – 0.60 1.50 – 6.00
Quenched and tempered steels ≥ 280 HB Average IT8225: 225 – 340 0.25 – 0.55 1.50 – 6.00

Guide values for the GR chipbreaker. Conditions not shown are not recommended for that material.

Internal turning (boring) of steels (ISO P) – GR chipbreaker

Starting values for internal turning with a boring bar, derived from this insert's external turning data: cutting speed −15%, feed −20%, maximum depth of cut −40%. Negative inserts are mounted on boring bars for bores from about Ø 25 mm upwards (Ø 32–40 mm for the larger sizes).

Material Condition Vc (m/min) by grade fn (mm/rev) ap (mm)
Structural steels ≤ 180 HB
(S235, C45…)		 Stable IT8115: 200 – 270
IT8125: 155 – 250
IT8225: 165 – 270		 0.20 – 0.48 2.00 – 4.20
Structural steels ≤ 180 HB
(S235, C45…)		 Average IT8115: 200 – 270
IT8125: 165 – 270
IT8225: 155 – 250		 0.20 – 0.44 2.00 – 4.20
Structural steels ≤ 180 HB
(S235, C45…)		 Difficult IT8115: 200 – 270
IT8125: 155 – 250
IT8225: 165 – 270		 0.20 – 0.40 2.00 – 4.20
Carbon and alloy steels 180 – 280 HB
(41Cr4, 42CrMo4…)		 Stable IT8115: 200 – 270
IT8125: 165 – 270
IT8225: 155 – 250		 0.20 – 0.48 2.00 – 4.20
Carbon and alloy steels 180 – 280 HB
(41Cr4, 42CrMo4…)		 Average IT8115: 200 – 270
IT8125: 165 – 270
IT8225: 155 – 250		 0.20 – 0.44 2.00 – 4.20
Carbon and alloy steels 180 – 280 HB
(41Cr4, 42CrMo4…)		 Difficult IT8115: 200 – 270
IT8125: 165 – 270
IT8225: 155 – 250		 0.20 – 0.40 2.00 – 4.20
Quenched and tempered steels ≥ 280 HB Stable IT8115: 190 – 305 0.20 – 0.48 1.50 – 3.60
Quenched and tempered steels ≥ 280 HB Average IT8225: 190 – 290 0.20 – 0.44 1.50 – 3.60

With a boring bar overhang above 3 times the diameter (steel bar) or 5 times (carbide or anti-vibration bar), reduce speed and feed further. Use the bar's internal coolant to clear the chips.