Diamond Inserts – Overview

???? What Are Diamond Inserts?

Diamond inserts are ultra-hard cutting tools used in turning, milling, grooving, and boring operations. They feature either:

• PCD (Polycrystalline Diamond): for non-ferrous and abrasive materials
• Single-Crystal Diamond: for ultra-fine finishing on non-metallic materials

They are known for extreme wear resistance, excellent surface finish, and long tool life, especially in high-speed machining of non-ferrous and composite materials.

???? Types of Diamond Inserts:

???? Common Shapes:

• CCGT, DCGT, VCGT (ISO standard turning inserts)
• Tipped inserts with PCD segments brazed on carbide
• Full-faced inserts for long-wear applications
• Custom profiles for grooves, radii, or specific contours

???? Applications of Diamond Inserts

Diamond inserts are ideal for machining:

• Aluminum (esp. with >10% Si content)
• Copper, brass, bronze
• Graphite electrodes
• CFRP / GFRP composites
• Plastics and thermosets
• Ceramics (non-ferrous types)

⚠️ Not for ferrous metals (e.g., steel) – diamond reacts with iron at high heat.

❓ Diamond Inserts – FAQ (Top 10 Questions)

1. What’s the difference between PCD and single-crystal diamond inserts?

• PCD is sintered diamond grit – tougher, used for general machining.
• Single-crystal diamond is ultra-sharp and ideal for micro-finishing and ultra-precision work.

2. Can I use diamond inserts on steel?

No. Diamond chemically reacts with iron, causing rapid wear. Use CBN inserts for steels or cast iron.

3. How long do diamond inserts last?

Up to 10–100 times longer than carbide in the right materials, especially in aluminum and graphite machining.

4. Are diamond inserts resharpenable?

Yes, PCD and single-crystal inserts can be reconditioned, but only by specialized grinding or laser services.

5. What industries use diamond inserts?

• Aerospace (composite machining)
• Automotive (aluminum parts)
• Electronics (graphite and ceramic machining)
• Medical (precision plastics)
• Tool & Die (graphite EDM electrodes)

6. What cutting conditions work best for diamond inserts?

• High-speed machining
• Stable setups (no vibration)
• Dry or MQL cutting (avoid coolant with certain plastics or composites)

7. Are there different grades of diamond inserts?

Yes – manufacturers offer different PCD grades (coarse or fine grain) for varying toughness and finish needs.

8. What is the typical surface finish from a diamond insert?

Diamond inserts provide a mirror-like surface finish, often <0.2 µm Ra, especially in plastics and aluminum.

9. Are diamond inserts cost-effective?

Yes. Though more expensive upfront, they reduce tool changes, improve finish, and eliminate secondary operations.

10. Do I need special holders for diamond inserts?

No – most are designed to fit standard ISO insert holders, especially turning, boring, and milling tools.