CBN Turning Inserts for CNC Lathes
Indexable CBN and PCBN turning inserts for hardened steel, cast iron, finish turning, profiling and continuous or interrupted lathe operations. Choose positive or negative ISO geometries, PCBN grades and edge configurations for the required cut.
Choose CBN Inserts by Turning Operation
Start with the machining movement and component access, then confirm the insert geometry, radius and grade.
Hard Finishing and Straight Turning
Use stable ISO shapes and application-matched nose radii for hardened-steel finishing, straight diameters and controlled surface generation.
Profiling and Contour Turning
D- and V-type geometries provide access for profile cuts, tapers and components with changing contours.
Internal Turning and Fine Boring
Positive insert geometries can reduce cutting forces where boring-bar rigidity, bore access and internal finishing are important.
Interrupted and Semi-Interrupted Turning
Select a tougher PCBN grade, stable insert body and suitable edge preparation where keyways, holes or interrupted surfaces increase impact.
Positive vs Negative CBN Turning Inserts
Choose the clearance and insert body according to cutting-force limits, edge strength, holder style and component access.
Negative CBN Turning Inserts
Zero-clearance insert bodies provide strong cutting edges and suit stable external turning, facing and selected interrupted operations.
Positive CBN Turning Inserts
Positive-clearance geometries can support lighter cutting, profiling, internal turning and applications with lower available rigidity.
| Selection Factor | Negative Insert Direction | Positive Insert Direction |
|---|---|---|
| Edge strength | Suitable when a strong insert body and stable setup are priorities | Suitable where reduced cutting force and access are priorities |
| Typical operation | External turning, facing and interrupted surfaces | Profiling, internal turning and lighter finishing |
| Catalog families | CNGA, DNGA, SNGA, TNGA, VNGA, WNGA | CCGW, DCGW, SCGW, TCGW, VCGW, WCGW |
| Final choice | Confirm holder compatibility, approach angle, workpiece access and required edge direction. | |
CBN Turning Inserts by Workpiece and Cutting Condition
Use the workpiece category and interruption level to narrow the PCBN grade and insert geometry.
| Workpiece / Condition | Typical Turning Goal | Insert Direction | Grade Direction |
|---|---|---|---|
| Acciaio temprato | Finish turning, diameter control and surface finish | C, D, T or V geometry according to access | OBN45, OBC50 or O2C50 for stable to lightly interrupted cuts |
| Bearing / case-hardened steel | Finish turning of hardened functional surfaces | Stable negative geometry or positive profile geometry | Lower-CBN grades for stable finishing; tougher grade as interruption increases |
| Grey or hard cast iron | Turning, fine boring and abrasive-material machining | Stable negative or positive boring geometry | OBW85 or OMB90 direction, subject to insert-code availability |
| Continuous / light interruption | Wear control and consistent finish | Geometry selected by operation and component access | OBN45, OBC50 or O2C50 direction |
| Moderate / heavy interruption | Improve edge reliability under impact | Stable insert body and suitable edge preparation | OBX60/OBX65 or OBW85 direction |
Final grade availability depends on insert code and tip structure. Confirm the catalog matrix before ordering.
CBN Turning Insert Starting Parameters
Use these ranges as a starting point for representative turning applications. Final speed, feed and depth of cut must be adjusted to the PCBN grade, insert geometry, hardness, interruption and machine rigidity.
| Materiale | Funzionamento | Cutting Condition | Vc (m/min) | ap (mm) | f (mm/rev) |
|---|---|---|---|---|---|
| Acciaio temprato | Turning / roughing | Continuous | 80–160 | 1.0–2.5 | 0.1-0.5 |
| Acciaio temprato | Turning / roughing | Interrupted | 80–125 | 1.0–2.5 | 0.1-0.5 |
| Acciaio temprato | Final turning | Continuous | 125–210 | 0.1-0.5 | 0.05-0.2 |
| Acciaio temprato | Final turning | Interrupted | 100–150 | 0.1-0.5 | 0.05-0.2 |
| Ghisa raffreddata | Final turning | General starting range | 70–160 | 0.1–1.0 | 0.1–0.35 |
| Grey Cast Iron GGG 20–30 | Final turning | General starting range | 800-2000 | 0.5–1.5 | 0.1–0.35 |
| Grey Cast Iron GGG 40–70 | Final turning | General starting range | 800-2000 | 0.3–1.3 | 0.2–0.3 |
Start from the lower half of the range for a new setup, long overhang, unstable clamping or interrupted cutting. Increase one parameter at a time after checking edge wear, dimensional stability and surface finish.
Select Edge Direction and Nose Radius
Edge direction and corner radius affect tool orientation, profile access, edge strength and the generated surface.
Nose Radius, Feed and Theoretical Surface Finish
Feed per revolution and cutting-edge radius influence the theoretical turned profile. Actual finish can still be affected by vibration, clamping, machine rigidity, insert wear and variable depth of cut.
Use the formula to estimate theoretical surface roughness from feed and nose radius.
| Target Ra | Rt | r = 0.2 | r = 0.4 | r = 0.8 | r = 1.2 | r = 1.6 |
|---|---|---|---|---|---|---|
| 0.8 | 1.8 | 0.05 | 0.07 | 0.10 | 0.12 | 0.14 |
| 1.6 | 4.0 | 0.08 | 0.11 | 0.15 | 0.19 | 0.23 |
| 3.2 | 10.0 | 0.12 | 0.17 | 0.24 | 0.29 | 0.36 |
| 6.3 | 16.0 | 0.16 | 0.22 | 0.30 | 0.37 | 0.45 |
Table values are feed f in mm/rev. The theoretical result does not include machine or workpiece instability, incorrect clamping, insert wear, edge damage or process vibration.
Choose a PCBN Grade for Turning
Move from wear-focused finishing grades toward tougher grades as cutting interruption and impact increase.
Confirm the final commercial naming of OBX60/OBX65 and the available grade matrix for each insert code before publishing.
Popular CBN Turning Insert Codes
Search representative negative and positive lathe insert codes from the catalog.
| Inserisci codice | Geometria | Turning Direction | Catalog Structure | Raggio del naso | Azione |
|---|---|---|---|---|---|
| CNGA120408 | Negative C-Type | General external turning / facing | 1N / 2N | 0,8 mm | Scopri il prezzo |
| CCGW09T304 | Tipo C positivo | Light turning / internal turning | 1N / 2N / Bordo intero | 0,4 mm | Scopri il prezzo |
| DNGA150408 | Negative D-Type | Profiling / shoulder access | 1N / 2N / Lato lungo | 0,8 mm | Scopri il prezzo |
| DCGW11T304 | Tipo D positivo | Profiling / internal turning | 1N / 2N | 0,4 mm | Scopri il prezzo |
| SNGA120408 | Negative S-Type | Stable external turning | 1N / 2N / Bordo intero | 0,8 mm | Scopri il prezzo |
| TNGA160408 | Negative T-Type | General turning / multiple corners | 1N / 3N / Intero bordo | 0,8 mm | Scopri il prezzo |
| TCGW16T304 | Tipo T positivo | Light turning / boring | 1N / Intero bordo | 0,4 mm | Scopri il prezzo |
| VNGA160404 | Negative V-Type | Profiling / contour access | 1N / 2N | 0,4 mm | Scopri il prezzo |
| VCGW160404 | Positive V-Type | Fine profiling / internal access | 1N | 0,4 mm | Scopri il prezzo |
| WNGA080408 | Negative W-Type | Economical multi-corner turning | 1N / 3N | 0,8 mm | Scopri il prezzo |
Looking for CNMG, TNMG, WNMG or another CBN lathe insert? Send the current code for a supply and cross-reference review.
How to Choose a CBN Turning Insert
Define the Operation
External turning, internal turning, facing, profiling or interrupted hard turning.
Choose the Geometry
Select positive or negative clearance, shape, holder compatibility and access.
Match the Grade
Use material hardness and interruption level to balance wear resistance and toughness.
Confirm Edge Details
Specify radius, ER/EL direction, tip count, chipbreaker or extended-edge requirement.
Turning Setup Information for Insert Selection
A reliable recommendation requires more than the insert code. Share the setup and current result so the insert geometry, radius, edge preparation and grade can be reviewed together.
CBN Turning Inserts Price and Supply Support
Price depends on the ISO code, PCBN grade, tip configuration, radius, edge preparation, order quantity and custom requirements.
CBN Turning Inserts: Common Questions
What are CBN turning inserts used for?
CBN turning inserts are used on CNC lathes for hard turning, hardened-steel finishing, cast-iron machining, profiling, boring and selected interrupted operations.
Which CBN insert shape is suitable for profiling?
D- and V-type insert geometries provide useful profile access. The final choice depends on holder style, contour, approach angle, required edge strength and whether the cut is external or internal.
Should I use a positive or negative CBN turning insert?
Negative inserts provide a strong body for stable turning, while positive inserts can reduce cutting force and improve access in profiling or boring. Holder compatibility and machine rigidity must also be considered.
Which PCBN grade is suitable for interrupted turning?
Tougher grades are generally selected as interruption increases. The correct grade depends on workpiece hardness, impact level, insert geometry, edge preparation and the current failure mode.
Can CBN turning inserts be used for internal turning?
Yes. Positive CBN insert geometries can be used for internal turning and fine boring when they match the boring bar, bore diameter, overhang and required approach.
What information is needed to quote a CBN turning insert?
Provide the insert code, workpiece material, hardness, turning operation, continuity of cut, current cutting data, current tool life and required quantity.
Can ONMY cross-reference a lathe insert code?
Send the current brand, full part number, grade and machining condition. ONMY can review the ISO geometry and available PCBN structure for a possible test alternative.
Request CBN Turning Insert Selection and Price
Send the turning operation, insert code and workpiece condition. Our team will review the geometry, radius, PCBN grade and quotation.
- Insert code, holder code, drawing or current brand part number
- External, internal, facing or profiling operation
- Materiale e durezza del pezzo
- Taglio continuo, con interruzioni leggere o con interruzioni frequenti
- Cutting speed, feed and depth of cut
- Current tool life, failure mode and required quantity
