CCMT09T304 is a positive-rake, 80-degree diamond-shaped carbide insert commonly used for internal boring, profiling, chamfering, and light turning operations. The designation generally identifies an insert with a 9.525 mm inscribed circle, approximately 2.38 mm thickness, and a 0.4 mm nose radius, although the exact dimensions and tolerance depend on the applicable standard and manufacturer. I recommend this insert when the boring bar has adequate clearance and the job requires low cutting resistance, controlled chip flow, and access to internal features. The correct carbide grade, chipbreaker, and cutting parameters must still be selected according to the workpiece material, bore diameter, machine rigidity, and coolant conditions.
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This guide is intended for CNC machinists, tooling engineers, purchasing teams, and distributors sourcing CCMT09T304 inserts for internal boring tools. It is also useful for buyers comparing general-purpose carbide grades with application-specific grades for steel, stainless steel, cast iron, or non-ferrous materials. I focus on practical selection rather than treating one insert specification as suitable for every machining condition. Actual performance should be confirmed through a controlled trial using the selected grade and cutting data.
CCMT09T304 belongs to the ISO-style family of positive turning inserts. The first letter, “C,” indicates an 80-degree included diamond shape, while “C” also provides a useful combination of strength and accessibility for many external and internal operations. The “M” typically indicates a defined tolerance class, and “T” identifies the insert’s hole and top geometry family. The remaining numbers identify size and corner-radius information within the designation system.
| Item | Typical CCMT09T304 reference | Why it matters |
|---|---|---|
| Insert shape | 80-degree diamond | Balances access, strength, and versatility |
| Inscribed circle | Approximately 9.525 mm | Determines compatibility with the toolholder |
| Insert thickness | Approximately 2.38 mm | Affects seating, clearance, and clamping |
| Nose radius | 0.4 mm | Influences finish, cutting force, and profile capability |
These values are common references for CCMT09T304, but I advise buyers to verify the supplier drawing before placing a production order. The insert must match the boring bar pocket, screw, seat, and clearance requirements. A dimensional mismatch can cause poor seating, insert movement, or damage to the toolholder. For this reason, the complete insert code and the compatible boring bar should be evaluated together.
CCMT09T304 is frequently selected for internal boring because its positive geometry can reduce cutting resistance compared with a more negative insert style. Its 80-degree shape provides access to internal shoulders and profiles while retaining more edge strength than sharper diamond geometries. The 0.4 mm nose radius is a practical compromise for general machining, although it may not be the best choice for very fine finishing or heavy interrupted cuts.
The insert is most effective when the boring bar is rigid, the overhang is minimized, and the insert orientation provides enough relief behind the cutting edge. Internal boring is more sensitive to vibration than many external turning operations because the tool is surrounded by the workpiece and often has a long unsupported length. I therefore treat CCMT09T304 as a versatile insert family rather than a universal solution for deep, unstable, or severely interrupted bores.
The CCMT09T304 geometry can be produced with different carbide substrates, coatings, chipbreakers, and edge preparations. A coated carbide grade for general steel may not deliver the same result in stainless steel or aluminum. When I select an insert, I first identify the ISO material group, then review hardness, surface condition, interruption level, coolant use, and the desired balance between tool life and surface finish.
| Workpiece category | Selection direction | Important caution |
|---|---|---|
| Low- and medium-carbon steel | General-purpose coated carbide with a suitable chipbreaker | Adjust for scale, forging skin, and interrupted cuts |
| Stainless steel | Tougher grade and geometry designed to control work hardening | Avoid rubbing and excessive dwell |
| Cast iron | Wear-resistant grade with an edge suited to abrasive chips | Manage dust and verify coolant policy |
| Aluminum and non-ferrous alloys | Sharp, polished geometry with adequate chip clearance | Use a grade and coating intended for non-ferrous machining |
For continuous finishing, a sharper edge may improve cutting action and surface quality. For roughing or interrupted machining, a stronger edge preparation may be safer, but it can increase cutting force. I recommend requesting the grade designation, chipbreaker range, coating description, and application chart from the supplier instead of purchasing based only on the CCMT09T304 shape code.
Cutting data should be treated as a starting point, not a guaranteed production setting. For a rigid CNC machine, stable workholding, and continuous cutting in mild steel, a conservative trial may begin around 100–180 m/min cutting speed, 0.08–0.18 mm/rev feed, and 0.3–1.0 mm radial depth of cut. These values can change substantially with insert grade, bore diameter, bar material, tool overhang, coolant, and the required surface finish.
| Parameter | Conservative starting range | Adjustment guidance |
|---|---|---|
| Cutting speed for mild steel | 100–180 m/min | Reduce speed if vibration, heat, or edge wear appears |
| Feed rate | 0.08–0.18 mm/rev | Use lower feed for finishing and smaller bores |
| Radial depth of cut | 0.3–1.0 mm | Increase only when rigidity and chip control are stable |
| Typical nose radius | 0.4 mm | Keep the programmed feed appropriate for the radius and finish target |
For stainless steel, I normally begin more cautiously and prioritize chip control, positive cutting action, and sufficient coolant delivery. For aluminum, a sharper non-ferrous geometry and higher speed may be appropriate, but the exact value depends on alloy, machine capability, and insert coating. Always calculate spindle speed from the selected cutting speed and bore diameter, then confirm that the machine can maintain the required speed without exceeding its limits.
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Start by matching the insert to the boring bar pocket and clamping screw. Check the insert size, thickness, hole form, clearance angle, and orientation shown on the supplier drawing. If the insert is intended for a specific bar family, verify that the bar provides the required clearance at the planned bore diameter.
Record the workpiece material, hardness, bore diameter, bore depth, allowance, tolerance, and surface-finish requirement. Then classify the operation as roughing, semi-finishing, finishing, or profiling. This information determines whether a tougher edge, sharper edge, stronger chipbreaker, or finer finishing geometry is most appropriate.
Use the largest practical boring bar and keep the unsupported length as short as possible. A long overhang can produce vibration even when the insert grade is suitable. If chatter occurs, reduce overhang first, check clamping, lower the radial depth of cut, and then adjust speed or feed systematically rather than changing several variables at once.
During the trial, inspect chips, edge wear, bore size, and surface finish after a defined cutting interval. A stable process generally produces controlled chips without excessive built-up edge, abnormal crater wear, or repeated edge chipping. If the insert wears quickly, review cutting speed and grade; if the edge chips, review interruption, depth of cut, clamping, and edge preparation.
One common mistake is ordering by “CCMT09T304” alone without specifying the carbide grade and chipbreaker. Another is assuming that a 0.4 mm nose radius will automatically produce a particular surface finish, even though feed rate, tool deflection, material, and machine condition also influence the result. Buyers should also avoid comparing price without considering insert consistency, packaging accuracy, technical support, and the supplier’s ability to maintain repeatable batches.
For internal boring, packaging and traceability are especially important when the same insert is used across multiple CNC machines. I recommend confirming the insert drawing, grade marking, inspection method, available quantity, production lead time, and sample policy before approving a new source. These checks reduce the risk of receiving a geometrically similar insert that does not perform in the original toolholder.
At KEUE CNC, we support B2B buyers who need CCMT09T304 carbide inserts for internal boring tools and related CNC applications. We can discuss insert geometry, carbide grade, coating direction, chipbreaker selection, packaging, and supply requirements based on the customer’s workpiece and machine conditions. Because cutting results depend on the complete machining system, I prefer to review the application details before recommending a production configuration.
CCMT09T304 is a practical choice for general internal boring when you need a positive, accessible insert with a 0.4 mm nose radius and a broad range of compatible carbide grades. It is not automatically the best option for every material, deep bore, interrupted cut, or finishing requirement. The most reliable selection combines the correct insert dimensions with a suitable grade, chipbreaker, rigid boring bar, and controlled starting parameters.
As the next step, prepare the workpiece material, bore diameter, bore depth, machine details, toolholder model, target tolerance, and surface finish. Send these specifications to KEUE CNC for a focused recommendation on CCMT09T304 grade, geometry, packing, and supply arrangement. I can help evaluate a trial configuration before you commit to a larger B2B order.
Contact us to discuss your requirements of ccmt09t304. Our experienced sales team can help you identify the options that best suit your needs.