Grinding Balls are used with Fritsch Planetary Mills and are placed into grinding bowls along with the sample to be ground. The final size of the sample after milling in a planetary mill is determined by the size and quantity of the grinding balls used. As a general guideline, larger balls will result in a coarser product and smaller balls will result in a finer product. It is not recommended to add balls of different sizes into the jar with the sample.
The selection of ball size and quantity for specific applications is best determined through user trials. In general, using more balls will reduce grinding times and yield finer size distributions until an optimum loading point is reached. However, it’s advisable not to exceed filling the bowl with balls and samples beyond two-thirds of its total volume. One-third of the bowl volume should be left for effective grinding action.
It is recommended to use grinding bowls and balls made of a material harder than the sample to be processed. For exceptionally hard samples, employing tungsten carbide balls in steel bowls or zirconium oxide balls in corundum bowls can enhance grinding efficiency. It’s important to note that when using dissimilar materials, there may be a risk of cross-contamination.
Balls with a 3mm diameter and smaller include 100 pieces. All other balls are sold individually. Classic Grinding Bowls or Premium Grinding Bowls are purchased separately.
| Material | Model No. | Size, mm dia. | Bowl Size Compatibility, mL |
|---|---|---|---|
Agate (SiO2)
| FTA-365 | 30 | 500, 250 |
| FTA-370 | 20 | 500, 250, 80 | |
| FTA-375 | 15 | 500, 250, 80 | |
| FTA-380 | 10 | 500, 250, 80 | |
| FTA-385 | 5 | 500, 250, 80 | |
Sintered Corundum (99.7% AI2O3)
| FTA-360 | 40 | 500 |
| FTA-366 | 30 | 500, 250, 80 | |
| FTA-371 | 20 | 500, 250, 80 | |
| FTA-376 | 15 | 500, 250, 80 | |
| FTA-381 | 10 | 500, 250, 80 | |
Zirconium Oxide (ZrO2)
| FTA-361 | 40 | 500 |
| FTA-367 | 30 | 500, 250 | |
| FTA-372 | 20 | 500, 250, 80 | |
| FTA-377 | 15 | 500, 250, 80 | |
| FTA-382 | 10 | 500, 250, 80 | |
| FTA-386 | 5 | 500, 250, 80 | |
| FTA-390 | 3 | 500, 250, 80 | |
| FTA-393 | 2 | 500, 250, 80 | |
| FTA-395 | 1 | 500, 250, 80 | |
Hardened Stainless Steel (Fe-Cr)
| FTA-362 | 40 | 500 |
| FTA-368 | 30 | 500, 250 | |
| FTA-373 | 20 | 500, 250, 80 | |
| FTA-378 | 15 | 500, 250, 80 | |
| FTA-383 | 10 | 500, 250, 80 | |
| FTA-387 | 5 | 500, 250, 80 | |
| FTA-391 | 3 | 500, 250, 80 | |
| FTA-396 | 1 | 500, 250, 80 | |
Hardmetal Tungsten Carbide (WC)
| FTA-369 | 30 | 500, 250 |
| FTA-374 | 20 | 500, 250, 80 | |
| FTA-379 | 15 | 500, 250, 80 | |
| FTA-384 | 10 | 500, 250, 80 | |
| FTA-388 | 5 | 500, 250, 80 | |
| FTA-392 | 3 | 500, 250, 80 | |
| FTA-394 | 1.6 | 500, 250, 80 | |
| FTA-397 | 0.6 | 500, 250, 80 |
