CBN MRMN Full Radius Grooving & Profiling Inserts

Achieve ultimate precision in full-radius grooving and profiling operations on hard ferrous materials with ZYsuperhard’s high-performance CBN MRMN indexable inserts. Specifically designed to create perfect semi-circular groove profiles, these inserts are ideal for applications like O-ring grooves and radius profiling where dimensional accuracy and surface finish are critical. Leverage the power of CBN to machine hardened steels, cast irons, and sintered metals effectively.

The CBN Advantage for Full Radius Grooving & Profiling

When machining hard ferrous materials (>45 HRC), traditional carbide inserts wear rapidly and cannot sustain high cutting speeds. ZYsuperhard’s CBN MRMN inserts overcome these limitations:

• Exceptional Hot Hardness: CBN retains its hardness at high cutting temperatures, enabling significantly faster cutting speeds (Vc) compared to carbide, drastically reducing cycle times.
• Superior Wear Resistance: Offers outstanding resistance to abrasive wear when machining hard or abrasive ferrous materials, leading to much longer tool life, fewer tool changes, and consistent groove profile accuracy.
• Excellent Surface Finish: The sharp, durable CBN edge produces superior surface finishes within the groove, often reducing or eliminating the need for secondary finishing operations.

Features of ZYsuperhard’s CBN MRMN Inserts

• Precise MRMN Geometry: Feature a full-radius cutting edge (r = Width W / 2) ground to tight tolerances, ensuring accurate semi-circular groove bottoms or precise profile generation. Designed for compatibility with standard MRMN tool holders.
• Robust Construction: A high-quality CBN cutting edge is securely brazed or sintered onto a tough carbide substrate, providing the optimal balance of extreme hardness at the edge and robust support from the base.
• Application-Specific CBN Grades: We understand that optimal performance depends on the right CBN grade. Various grades are available, typically differing in CBN content and binder type:
  • Low CBN Content Grades: Generally preferred for continuous cutting in hardened steels, offering excellent chemical wear resistance at high temperatures.
  • High CBN Content Grades: Offer increased toughness, making them better suited for interrupted cuts or machining cast irons and sintered metals.
  • Recommendation: Selecting the best grade depends heavily on your specific material (including its exact hardness), and whether the cut is continuous or interrupted. Please consult with our technical team to determine the ideal grade for your application.
• Available Edges: In addition to our standard 1-edge (single-ended) inserts, a 2-edge (double-ended) configuration is available, delivering enhanced economy with two cutting edges per insert.
• Customizable Edge Preparations: To maximize tool life and performance based on your specific cutting conditions, various edge preparations are available upon request:
  • Hone: Light edge rounding for finishing or stable cuts.
  • Chamfer: Provides increased edge strength for general use.
  • T-Land (Negative Land): Offers maximum edge protection for interrupted cuts or demanding applications.
  • Recommendation: The optimal edge preparation depends on factors like material, cut type (continuous/interrupted), and whether you prioritize finish or edge security. We strongly recommend discussing your application with us to select the best edge preparation.

Applications & Material Suitability

ZYsuperhard’s CBN MRMN inserts excel in:

• O-Ring Grooves: The primary application, creating precise, smooth round-bottom grooves for O-ring seals.
• Radius Seal Grooves: Machining grooves requiring a specific full radius bottom for other types of seals.
• Radius Profiling: Generating external or internal profiles with a defined radius on hard materials.

Suitable Workpiece Materials:

• Hardened Steels: Typically > 45 HRC, including case-hardened, induction-hardened, and through-hardened steels.
• Cast Irons: Grey Cast Iron, Ductile Iron, Compacted Graphite Iron (CGI).
• Sintered Metals / Powder Metallurgy (PM) Parts: Especially ferrous-based PM components.
• Hard Facing Alloys: Certain applications on wear-resistant overlays.

Cutting Parameter Guidance

Achieving optimal results with CBN MRMN inserts requires careful parameter selection:

• Cutting Speed (Vc): CBN allows for significantly higher speeds than carbide on hard materials. The specific optimal range depends heavily on the chosen CBN grade, material hardness, and machine stability.
• Feed Rate (f): Needs to be balanced to ensure good surface finish and chip control without overloading the cutting edge. Lower feeds are typically used for finishing and higher precision.
• Depth of Cut (Ap): For grooving, strategy often involves multiple passes for deeper grooves to manage chip evacuation and tool pressure. For profiling, Ap depends on the operation type.

Important Note: Optimal cutting parameters are highly dependent on the specific CBN grade selected, workpiece material details (hardness, composition), machine rigidity, coolant application (wet cutting is often recommended for steels), and the required outcome (surface finish, tool life). Starting parameters should be based on our recommendations for the specific grade and application, followed by careful testing and optimization.

Tool Holder Compatibility

Always use these MRMN inserts with high-quality, rigid tool holders specifically designed for the MRMN insert type and size to ensure secure clamping, accurate positioning, and optimal performance. To ensure optimal performance, we can also supply compatible tool holders if required.

Customization & Ordering

ZYsuperhard specializes in providing solutions tailored to your needs. While common widths (e.g., 2.0mm, 3.0mm, 4.0mm) are often requested, these CBN MRMN inserts are frequently customized regarding:

• Specific Groove Width (W) and Tolerance
• Optimal CBN Grade Selection
• Required Edge Preparation
• Other potential modifications

Please contact our technical sales team with details about your application (workpiece material & hardness, groove dimensions & tolerances, machine type, continuous/interrupted cut, etc.). We will work with you to recommend or design the ideal CBN MRMN insert solution and provide a quote.