Diamond Sharpening Stone Grit Guide: How to Choose 80–1200 Grit
A useful rule is:
Start with the finest grit that can restore the edge efficiently.
Starting too coarse removes more steel than necessary. Starting too fine can make sharpening unnecessarily slow.
This guide explains when to use SHARPAL electroplated diamond sharpening stones and plates in 80, 220, 325, 600, 1000, and 1200 grit, how to choose the right starting grit, and when to move to a finer stone.
Diamond Sharpening Stone Grit Chart
Use the chart below as a quick reference for choosing a starting grit based on the condition of the edge.
| Grit | Particle Size | Best For | Typical Use |
|---|---|---|---|
| 80 | 180 µm | Heavy repair | Major edge damage or significant reprofiling |
| 220 | 60 µm | Repair | Chipped, damaged, or severely dull edges |
| 325 | 45 µm | Sharpening | Normally dull knives and tools |
| 600 | 25 µm | Sharpening & refinement | Light sharpening or refining a coarse edge |
| 1000 | 15 µm | Fine refinement | Finishing routine sharpening |
| 1200 | 12 µm | Fine honing | Refining or maintaining an established edge |
These grit and particle-size specifications apply to the SHARPAL electroplated diamond sharpening stones and plates referenced in this guide. Grit ratings and grit-to-micron conversions are not universal and can vary between abrasive standards and manufacturers. When comparing diamond sharpening products from different brands, refer to the manufacturer’s stated micron size when available.
Which Grit Should You Start With?
Choose your starting grit according to the condition of the edge.
| Edge Condition | Recommended Starting Grit |
|---|---|
| Major chips or significant reprofiling | 80 |
| Small chips, damage, or severely dull edge | 220 |
| Normally dull edge | 325 |
| Slightly dull edge that still cuts reasonably well | 600 |
| Established edge needing a touch-up | 1000 or 1200 |
These are practical starting points rather than fixed rules. If you are unsure, start with the finer option. If progress is too slow, move to a coarser grit.
How Do You Know If the Starting Grit Is Right?
After several controlled sharpening passes, check the bevel and edge.
Stay with the grit if the bevel is developing efficiently, fresh scratches are reaching the edge, and a small, consistent burr can begin to form.
Move coarser if very little steel is being removed, chips are not disappearing, or re-establishing the bevel is taking excessively long.
The goal is to use enough cutting power to restore the edge efficiently without unnecessary steel removal.
80 vs. 220 Grit: Heavy Repair vs. Repair
Both are coarse abrasives, but they serve different levels of repair.
80 grit is extremely aggressive and is best reserved for major chips, heavy material removal, or significant reprofiling.
220 grit is a more practical repair grit for smaller chips, severely dull edges, and general edge restoration. It cuts quickly while being less aggressive than 80 grit.
For a normally dull knife without visible damage, neither grit is usually necessary.
325 vs. 600 Grit: Which Is Better for Routine Sharpening?
For most routine sharpening, the main choice is between 325 and 600 grit.
Choose 325 grit when the knife has clearly lost its working sharpness, the bevel needs to be re-established, or 600 grit would take too long. SHARPAL 325 grit uses approximately 45 micron diamond particles.
Choose 600 grit when the edge is only slightly dull, still cuts reasonably well, and mainly needs light sharpening or refinement. SHARPAL 600 grit uses approximately 25 micron diamond particles.
If 600 grit is working efficiently, there is no reason to move coarser. If progress is very slow, step back to 325 grit.
1000 vs. 1200 Grit: Do You Need Both?
Usually, no.
Once the edge geometry has been established, 1000 or 1200 grit can serve as a practical final diamond refinement stage for many working edges.
SHARPAL 1000 grit uses approximately 15 micron diamond particles, while SHARPAL 1200 grit uses approximately 12 micron diamond particles.
Both are suitable for refining scratches from coarser grits, maintaining an established edge, and fine finishing.
Because the difference between 1000 and 1200 grit is relatively small, they are better viewed as alternative fine finishing grits rather than mandatory consecutive steps.
When Should You Move to a Finer Grit?
Move to the next grit only after the current grit has completed its job.
On the starting grit, that generally means the damage has been corrected, the bevel has been properly established to the apex, and a small, consistent burr can begin to form.
There is no benefit in deliberately creating an unnecessarily large burr.
Once the edge is established, finer grits are used mainly to refine the scratch pattern and reduce or remove the remaining burr rather than to remove significant amounts of steel.
Moving finer too early usually makes sharpening slower, not better.
Do You Need to Use Every Grit?
No. Use only the stages required by the condition of the edge.
| Blade Condition | Practical Progression |
|---|---|
| Major repair or reprofiling | Start at 80, then refine as needed |
| Chipped or severely dull | 220 → 600 |
| Normally dull | 325 → 1000 or 1200 |
| Slightly dull | 600 → 1000 or 1200 |
| Established edge / touch-up | 1000 or 1200 |
There is no need to work through 80 → 220 → 325 → 600 → 1000 → 1200 every time. Skipping unnecessary stages saves time and reduces steel removal.
Does a Higher Grit Always Produce a Better Edge?
No. Higher grit means finer refinement, not automatically better cutting performance.
A 600-grit finish can leave a crisp, slightly more aggressive or “toothy” working edge that performs well for many everyday cutting tasks.
A 1000- or 1200-grit finish produces a more refined edge with a finer scratch pattern.
The best stopping grit depends on what you are sharpening, how the blade will be used, and the edge finish you prefer.
Practical Diamond Stone Grit Combinations
For damaged or severely dull edges, a 220/600 grit combination provides an efficient progression from repair to refinement. SHARPAL diamond sharpening stones such as the 163N and 169H use this combination.
For routine sharpening, a combination beginning with 325 grit and finishing at 1000 or 1200 grit provides a practical progression from restoring a dull edge to fine refinement. SHARPAL bench stones such as the 162N, 168H, and 156N use these grit ranges. The current SHARPAL 162N specification confirms 325 grit / 45 µm and 1200 grit / 12 µm.
Choose the combination that matches the knives and tools you sharpen most often rather than simply choosing the highest grit available.
Frequently Asked Questions
What grit diamond stone should I use for a dull knife?
For a normally dull knife without major damage, 325 grit is a practical starting point. If the knife is only slightly dull and still cuts reasonably well, try 600 grit first.
Should I use 220 or 325 grit?
Use 220 grit for chipped, damaged, or severely dull edges. Use 325 grit for normal sharpening when the edge is dull but otherwise intact.
Is 600 grit enough to sharpen a knife?
Yes, in many cases. If the edge geometry is already established, 600 grit can provide effective general sharpening and leave a useful working edge. For a badly damaged or severely dull blade, start coarser.
Is 1000 grit enough for finishing a knife?
Yes. For an established edge, 1000 grit is well suited to fine refinement and finishing. A 1200-grit stone provides a slightly finer refinement option, but using both is usually unnecessary.
Final Thoughts
The best diamond sharpening stone grit is the one that matches the condition of the edge and the work that needs to be done.
Start with the finest grit that can restore the edge efficiently. If progress is too slow, move coarser. Once the edge is established, move finer only when additional refinement is needed.
This approach keeps sharpening efficient, controlled, and avoids removing more steel than necessary.