CNMG120408CJ CA115P TML00085

Product Overview

The CNMG120408CJ CA115P TML00085 is a precision-engineered indexable carbide turning insert manufactured by Kyocera in Japan. Designed for steel roughing, this medium-roughing chipbreaker insert combines a fine-grained carbide substrate with an advanced TiAlN PVD coating to deliver exceptional performance in CNC turning centers and milling machines.

With an 12.700 mm (1/2") inscribed circle, 4.760 mm (3/16") thickness, and 0.8 mm (1/32") nose radius, the CNMG120408CJ offers balanced geometry for versatile general-purpose machining. The medium-roughing chipbreaker geometry ensures reliable chip control across a wide range of feed rates and depths of cut, making it an ideal choice for reliable general production environments.

ISO Designation Breakdown

The CNMG120408CJ follows the ISO 1832 standard insert designation system, providing complete geometric and tolerance information at a glance:

• C – Insert shape: 80° rhombic (diamond) with acute corners, ideal for versatile turning and facing operations
• N – Normal clearance angle: 0°, providing maximum edge strength for heavy-duty applications
• M – Tolerance class: ±0.08 mm on inscribed circle (IC), ±0.05 mm on thickness (S), ±0.13 mm on corner height
• G – Hole and chipbreaker type: Cylindrical hole with counterbore, chipbreaker on both rake faces (double-sided usability)
• 12 – Inscribed circle diameter: 12.700 mm (1/2")
• 04 – Nominal thickness: 4.760 mm (3/16")
• 08 – Corner radius: 0.8 mm (1/32") – balanced edge for general purpose
• CJ – Chipbreaker code: Medium-Roughing Chipbreaker for Steel Roughing

Engineering Dimensions & Geometry

Precision-machined dimensions ensure perfect seat contact and repeatability in CNC toolholders:

The 0° clearance angle (N-type) provides a straight flank that seats firmly against the toolholder pocket, maximizing stability during aggressive cuts. The medium-roughing chipbreaker geometry is precision-ground to ±0.015 mm form accuracy.

Grade Details - Key Grade Characteristics

The CA115P grade is a premium PVD-coated carbide specifically engineered for steel turning applications. Key characteristics include:

• Substrate: Fine-grained tungsten carbide with high cobalt content for optimal toughness
• Coating System: Multi-layer PVD coating with TiAlN-based architecture
• Coating Color: Bronze-copper – visual wear indicator for easy tool-life monitoring
• Microhardness: HRA 91.5 – balancing hardness and toughness
• TRS: ≥ 2,800 MPa – high mechanical strength resists chipping
• ISO Application: ISO P15–P30 (Steel machining)
• Max Operating Temp: 800°C (1,472°F)
• Wear Performance: Excellent crater and flank wear resistance in continuous to medium-interrupted cutting

The TiAlN-based PVD coating delivers exceptional oxidation resistance and thermal stability, maintaining coating integrity at elevated cutting temperatures typical in steel machining. The fine-grained substrate structure minimizes crack propagation, extending insert life in both continuous and interrupted cuts.

Grade Comparison Matrix

Chipbreaker Profile

The CJ chipbreaker on the CNMG120408CJ is specifically designed for steel roughing:

• Reinforced cutting edge
• Reliable chip control at medium feeds
• High stability in interrupted cutting
• Excellent heat dissipation

Robust medium-to-roughing chipbreaker with reinforced cutting edge for demanding applications. Handles interrupted cuts and variable depths with reliable chip evacuation. The chipbreaker land width is optimized for the 0.8 mm (1/32") nose radius, ensuring proper chip curl and breakage without compromising edge integrity. Chip flow angle is designed to direct chips away from the workpiece surface, preventing scratching and ensuring safe evacuation.

Recommended Applications & Workpiece Materials

The CNMG120408CJ with CA115P grade is optimized for the following workpiece materials and operations:

• Primary Materials: Carbon steel, alloy steel, tool steel, cast steel (ISO P20-P30)
• Hardness Range: 80–350 HB (ideal up to 280 HB for optimal tool life)
• Surface Condition: Suitable for standard mill-scale and machined surfaces
• Machine Types: CNC turning centers, multi-tasking machines, Swiss-type lathes, conventional engine lathes with proper holders

For best results, ensure rigid workpiece clamping and minimal tool overhang. Use high-pressure coolant (70+ bar) for deep-hole boring applications to improve chip evacuation and surface finish.

Application Map by Operation

Recommended Cutting Conditions

Recommended starting parameters for steel roughing with CA115P:

Coolant Recommendation: Water-soluble coolant (5–10%) recommended for optimal tool life and surface finish. For dry machining, reduce cutting speed by 15–20%.

Operating Guidelines

• Toolholder Selection: Use M-class holders (MCLNR/L, MCKNR/L) with matching shim seat for 12.700 mm (1/2") inserts. Ensure holder pocket is clean and undamaged.
• Insert Seating: Verify full contact between insert bottom and shim seat. A 0.02 mm feeler gauge should not pass under the insert when properly seated.
• Clamping Torque: Tighten lever to 2.5–3.5 N·m. Over-tightening can distort the insert; under-tightening causes vibration and poor finish.
• Run-out Check: Maintain radial run-out <0.01 mm at the cutting edge. Excessive run-out causes uneven wear and poor surface finish.
• Entry Strategy: Prefer arc-in entry for best surface finish; direct entry acceptable for roughing
• Edge Life Monitoring: Monitor flank wear (VB). Replace insert when VB reaches 0.3 mm for roughing or 0.15 mm for finishing to maintain dimensional accuracy.
• Chip Control: If chips are too long or bird-nesting, increase feed by 10% or verify coolant delivery to the cutting zone.

Toolholder Compatibility

• External Turning: MCLNR/L, MCKNR/L, MCMNN (95° toolholders with 80° insert seat)
• Internal Boring: S20R-MCLNR11, S25S-MCLNR12 (boring bars with CNMG pocket)
• Facing: MCFNR/L (45° face milling style holders)
• Profiling: MDJNR/L (93° approach angle for copy turning)
• Clamp System: Lever lock or top-clamp systems compatible with M-class inserts
• Shim Requirement: Use matching shim seat (e.g., MC1204, MC1606) for optimal support

Packaging & Ordering Information

• Standard Pack: 10 inserts per plastic box (industry standard)
• Individual Packaging: Each insert protected in anti-vibration foam slot
• Labeling: Box includes grade, model, batch number, and barcode for traceability
• Bulk Orders: Master cartons of 100 inserts (10 boxes) available for OEM/institutional buyers
• Storage: Store in original packaging at 15–25°C, humidity <60% RH
• Shelf Life: 5 years from date of manufacture when stored properly

Catalog Meta Data

• Catalog Series: Kyocera Turning Inserts – Standard Line
• Revision Date: 2026-Q2
• Replacement For: Compatible with all ISO-standard CNMG holders (ANSI C-shape)
• RoHS Compliance: Fully compliant with EU RoHS Directive 2011/65/EU
• REACH Status: No SVHC substances above threshold (as per 2026 candidate list)
• Origin: Manufactured in Japan under ISO 9001:2015 and ISO 14001:2015 certified facilities