PCD and PCBN tools are some of the most expensive consumables in a machine shop. A single worn insert can cost a lot to replace. But here is the good news: resharpening those tools with the right diamond grinding wheel can restore their cutting performance and save you 25% to 75% compared to buying new ones. This guide gives you the straight facts on how to grind PCD and PCBN efficiently, what wheels to use, and how to avoid the most common mistakes. No unnecessary theory, only what works on the shop floor.

Why you need a diamond wheel (and only diamond)

PCD (polycrystalline diamond) and PCBN (polycrystalline cubic boron nitride) are the hardest tool materials you will ever grind. Conventional aluminum oxide or silicon carbide wheels simply cannot cut them. They glaze, burn the edge, and wear out in seconds. For both PCD and PCBN, you need a diamond grinding wheel.

• For PCD tools, diamond abrasive matches the hardness of the diamond layer and removes stock with minimal heat.

• For PCBN tools, diamond is still the practical choice. PCBN is slightly less hard than diamond, and a well‑cooled diamond wheel gives you the removal rate and edge quality you need.

If you try to grind these materials with anything else, you are wasting time and money.

Choosing the right bond: vitrified is the workhorse

The bond holds the diamond grit in place. Which one you pick changes how the wheel behaves. In more than 90% of the PCD and PCBN grinding jobs we see, vitrified (ceramic) bond diamond wheels are the best starting point and the safest long‑term solution.

Vitrified Bond – The proven standard

Norton Winter, one of the largest grinding technology companies in the world, says it clearly: “Vitrified bond diamond grinding wheels have now become the standard for the majority of PCD and PCBN tool grinding operations.” Here is why our customers keep coming back for them:

• They stay sharp by themselves: The porous structure lets dull diamond grains fall out naturally, so fresh grains are always exposed. This means fewer burns, a consistent cut, and less time spent on dressing.

• They remove stock fast: In many applications, a vitrified wheel reduces grinding time by around 40% compared to a resin wheel. That is a direct saving in labour and machine cost.

• They hold their shape: The stiff bond keeps the wheel profile accurate over hundreds of edges, which is critical when you need consistent angles and radii on inserts.

• They last: A vitrified diamond wheel typically lasts 2.5 to 3 times longer than a resin wheel on the same job.

Our recommendation: If you run a standard PCD or PCBN grinding operation — manufacturing new tools, resharpening worn inserts, or regrinding damaged edges — stick with vitrified diamond wheels for the whole process. One wheel type, from roughing through finishing, simplifies your inventory and gives you predictable results.

Other bond types – niche solutions for specific needs

We stock and supply all bond types, but we want to be honest about where they fit. If a customer asks about alternatives, here is what we tell them:

• Resin bond – Softer cutting action, sometimes used for a final super‑finish pass when surface roughness requirements are extreme. It is not a replacement for vitrified; it is a complementary finish wheel. Resin wheels wear faster and need more frequent replacement, but in a specific, well‑cooled finishing step they can reduce edge chipping very slightly compared to a standard vitrified finish wheel. For most shops, sticking with a fine‑grit vitrified wheel is simpler and more cost‑effective.

• Metal bond – Extremely tough and keeps a profile forever, but cuts slowly and can “glaze” or rub against PCD and PCBN if not dressed constantly. We only recommend metal bond wheels for rough pre‑grinding of large batches where profile holding is the absolute priority, or for special profiled tools. For daily regrinding, metal bond is usually not the right choice because it generates too much heat and requires more frequent dressing.

• Hybrid bonds – Newer technology that blends resin and metal, or ceramic and metal. They try to give the free‑cutting of ceramic with a bit more life. Some hybrid wheels do work well, but they are more expensive and not necessary for most customers. If you have a very high‑volume production line and want to explore a custom solution, we can help, but for nearly every shop, a good vitrified wheel does the job.

Bottom line: Vitrified diamond wheels are your everyday solution. The other bond types exist, and we can supply them if your process genuinely needs them, but most of our customers never move away from vitrified after they try it.

Grit size: the single most important number

Get the grit wrong, and you will either chip the cutting edge or work too slowly. Here is a simple way to think about grit selection for PCD and PCBN.

For resharpening, match the grit to the damage:

• Severely broken edge (damage around 0.5 mm): Start with a D46 vitrified diamond wheel to clear the damage fast.

• Moderate edge collapse (about 0.3 mm): A D20 wheel gives you speed and control.

• Just a dull edge (wear less than 0.1 mm): Go straight to D10 or D15 for finishing.

In a typical shop, we recommend keeping at least two vitrified diamond wheels: one coarser wheel (D20–D46) for reshaping, and one finer wheel (D10) for finishing. This two‑step approach gives you fast cycle times and a sharp edge every time.

Simple grinding parameters that work

You do not need a research paper to set up your grinder. Stick to these ranges for vitrified diamond wheels on PCD and PCBN, and you will be in the right area.

• Wheel speed: 15–25 m/s (20 m/s is a safe all‑round number)

• Depth of cut – roughing: 0.02–0.05 mm per pass

• Depth of cut – finishing: 0.005–0.01 mm per pass

• Oscillation: around 60 strokes per minute

• Spark‑out passes: 3 to 8 passes at zero infeed to clean up the edge

• Coolant: water‑mixed emulsion, 3–5% concentration, good flow

A few rules that save wheels and tools:

• Always apply the depth of cut before the wheel enters the cutting zone. This avoids impact loads that chip the diamond grit.

• If you see chatter or poor finish, check your machine. A worn spindle or poor balance will ruin any wheel’s performance.

• Dress the wheel regularly with a vitrified dressing stick to remove loaded material and expose fresh diamond.

Common problems and how we solve them

We have seen these issues in shops all over the world. Here is what to check.

• Edge chipping too big: Your finishing grit is too coarse, or you are taking too much depth. Switch to a finer wheel (D10 or D15) and reduce infeed to 0.01 mm or less.

• Burn marks or vertical streaks: The wheel is loaded and rubbing instead of cutting. Dress it. If the problem continues, you may need a vitrified bond with higher porosity.

• Wheel wears out too fast: Speed may be too low, or the bond is too soft. Try increasing the speed within the recommended range, or ask us about a harder grade.

• Wheel cuts too hard (slow, burns): Speed may be too high. Reduce it to 15–18 m/s and dress more often.

• Edge quality changes from insert to insert: This usually points to machine issues — check spindle bearings and wheel mounting.

• Diamond grit wears quickly when grinding PCBN: While diamond is correct for PCBN, some PCBN grades contain metallic binders that, together with high heat, can accelerate diamond wear. Improve coolant flow, reduce your depth of cut per pass, and make sure the speed is not too high.

Why resharpening makes financial sense

The math is simple: a resharpened PCD or PCBN tool cuts like new, and it costs a fraction of a new tool. When you do it in‑house with the right diamond wheels, you also cut lead times and stop paying to scrap expensive carbide bodies. Most carbide‑tipped PCD tools can be resharpened 2–3 times before the diamond layer becomes too thin. Solid PCBN inserts often allow even more regrind cycles.

Investing in a pair of good vitrified diamond wheels pays for itself after only a handful of tools.

We supply the right diamond wheel for your exact job

We are a diamond and CBN grinding wheel supplier with deep experience in PCD and PCBN tool grinding. We stock and supply:

• Vitrified diamond wheels – the workhorse for PCD and PCBN in all standard shapes: 6A2, 12A2, 11V9, 1A1

• Resin bond diamond wheels – for special fine finishing passes when required

• Metal bond diamond wheels – for rough pre‑grinding or profile work

• Hybrid bond wheels – for high‑volume jobs that need a tailored solution

Our wheels fit all common tool grinders, including EWAG, Vollmer, Coborn, Agathon, and manual machines. Tell us your tool type, the damage you typically see, and the machine you run. We will recommend a complete diamond wheel package that puts a vitrified wheel at the core of your process, and we will back it up with field‑proven results.

Get in touch with our technical team today and let’s put the right diamond wheel on your grinder.