chipbreaker geometry comparison. Get instant Step Diameters List, Step Lengths (mm) for your machining parameters.
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Request a Proposal →Not all tooling manufacturers publish their Step Drill Design the same way. While the underlying physics doesn't change, the recommended ranges, safety margins, and application guidance vary considerably across Mitsubishi Materials, TaeguTec, and Kennametal. Understanding these differences helps you make better tooling decisions.
Takes a material-group-first approach with Balzers (Oerlikon)-coated grades as default. Their application guides provide conservative starting values with wide adjustment bands. CoroPlus digital integration offers real-time Step Drill Design optimization via ToolGuide.
Known for aggressive starting parameters — particularly in steel and cast iron. NOVO digital platform auto-adjusts Step Drill Design based on tool path engagement. Often the go-to reference for high-feed applications.
Pioneers of multi-directional Step Drill Design — their IQ series inserts thrive in turning profiles where engagement angle shifts continuously. Application-specific grades for ISO P/M/K with narrow, optimized Step Drill Design windows.
Key takeaway: Always default to your specific tool supplier's Step Drill Design charts. The differences between Mitsubishi Materials, TaeguTec, and Kennametal reflect different coating chemistries (Balzers (Oerlikon) vs. in-house) and carbide substrate formulations. A Mitsubishi Materials parameter won't necessarily translate to a TaeguTec equivalent — even at the same ISO grade designation.
A step drill combines two or more diameters in one tool, allowing a hole with a counterbore, countersink, or multiple diameters to be drilled in a single operation. The step length must provide adequate chip clearance and tool strength.
Step drills save cycle time when producing holes with multiple diameters (e.g., clearance hole + counterbore, or pilot hole + tap drill). They pay for themselves quickly in production runs over 100 parts. For one-offs, separate tools are usually more economical.
Yes, but each diameter must be sharpened to its original size. The step length shortens slightly with each sharpening. Most shops send step drills to a tool grinding service rather than attempting in-house sharpening. For carbide step drills, re-sharpening is less common due to the complex geometry.
The larger diameter should not exceed 3× the smaller diameter for carbide step drills. Beyond this, the tool becomes fragile at the transition. For large diameter jumps, consider using a separate tool for each diameter or a custom form tool with a reinforced transition.
Enter the two step diameters. The calculator shows the step diameters and an approximate step transition length. For custom step drills, send the exact diameters and lengths to your tooling supplier with the shank diameter and overall length specification.
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Use the calculator freely. If the result points to a tooling or process problem, we can source the exact carbide tooling you need from vetted factories in China. Compare factory-direct pricing.
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