Quick Answer: Abrasive grit sizes are classified under several systems: GB (China), FEPA (Europe), JIS (Japan), and AFS (U.S. Foundry). Conversion tables allow users to translate grit numbers between standards—for example, FEPA F100 ≈ JIS #120 ≈ GB 100 ≈ AFS ~60. Use these charts as a practical reference when sourcing or specifying abrasives across regions.
Why Conversion Matters
Different markets and industries use different abrasive standards. FEPA dominates Europe and global packaging, JIS is common in Asia, GB applies within China, and AFS is specific to foundry sand fineness. Without conversion, buyers risk ordering the wrong grit size. Conversion tables bridge this gap and ensure consistent performance across suppliers.
GB–FEPA–JIS–AFS Conversion Tables
The following tables provide approximate equivalence between grit size standards. Always check the latest official documents for exact tolerances.
Coarse Grits (Grinding & Blasting)
| Approx. Particle Size (μm) | FEPA (F) | FEPA (P) | JIS | GB | AFS (GFN) |
|---|---|---|---|---|---|
| ~1410 | F12 | P12 | #12 | GB 12 | AFS ~12 |
| ~355 | F46 | P40 | #36 | GB 46 | AFS ~30 |
| ~125 | F100 | P120 | #120 | GB 100 | AFS ~60 |
Medium Grits (General Grinding & Sanding)
| Approx. Particle Size (μm) | FEPA (F) | FEPA (P) | JIS | GB | AFS (GFN) |
|---|---|---|---|---|---|
| ~60 | F240 | P240 | #240 | GB 240 | AFS ~90 |
| ~36 | F400 | P400 | #600 | GB 400 | AFS ~100 |
Fine & Micro Grits (Polishing & Lapping)
| Approx. Particle Size (μm) | FEPA (F) | FEPA (P) | JIS | GB | AFS |
|---|---|---|---|---|---|
| ~25 | F600 | P600 | #1500 | GB 600 | – |
| ~12 | F1200 | P1200 | #4000 | GB 1200 | – |
Practical Examples
- Example 1: A European buyer requests FEPA F100 grit. A Chinese supplier can provide GB 100 or JIS #120 as equivalents.
- Example 2: A lapidary polisher using JIS #1500 can cross-reference to FEPA F600 / P600 for sourcing sandpaper.
- Example 3: Foundry sand specified at AFS 60 correlates roughly to FEPA F100 (~125 μm).
FAQs
Are these conversions exact?
No. They are approximate equivalences based on average particle sizes. Always confirm tolerances from official standards.
Why does JIS #1200 differ from FEPA P1200?
JIS defines tighter tolerances for microgrits, so equivalence must be checked carefully.
Is AFS directly comparable to FEPA or JIS?
Not directly. AFS measures sand fineness (GFN) for casting; comparison is approximate at best.
References
- FEPA Abrasives Standards (F and P grit series).
- JIS R6001 Grit Size Standard.
- GB/T 2481 Abrasive Grain Size Standard.
- AFS Foundry Sand Testing Handbook.
