Where to farm Grindstone Pentahydrate in Arknights, what to craft it from, and which operators need it.
| Stage | Drop tier | ~Sanity/ea |
|---|---|---|
| 4-8 · byproduct | Sometimes | ≈150.0 |
| 7-17 · byproduct | Sometimes | ≈150.0 |
| 12-8 · byproduct | Sometimes | ≈150.0 |
| 14-5 · byproduct | Sometimes | ≈150.0 |
| 13-21 · byproduct | Sometimes | ≈171.4 |
To make 1 of [object Object]: Grindstone×1 + Oriron Cluster×1 + Integrated Device×1
| Operator | Rarity | Qty |
|---|---|---|
| Mostima | 6★ | 18 |
| Andreana | 5★ | 17 |
| Ch'en the Holungday | 6★ | 15 |
| Frost | 5★ | 15 |
| Fiammetta | 6★ | 14 |
| Suzuran | 6★ | 13 |
| Skadi | 6★ | 13 |
| Civilight Eterna | 6★ | 13 |
| Siege | 6★ | 13 |
| Angelina | 6★ | 13 |
| Exusiai | 6★ | 13 |
| Weedy | 6★ | 13 |
| Ifrit | 6★ | 13 |
| Ch'en | 6★ | 13 |
| Muelsyse | 6★ | 12 |
| Yu | 6★ | 12 |
| Amiya | 5★ | 12 |
| Warmy | 5★ | 12 |
| Shining | 6★ | 11 |
| Hoshiguma | 6★ | 11 |
| Bison | 5★ | 11 |
| Sesa | 5★ | 11 |
| Ash | 6★ | 10 |
| Blacknight | 5★ | 10 |
| Cantabile | 5★ | 10 |
| Firewhistle | 5★ | 10 |
| Gavial the Invincible | 6★ | 9 |
| Nearl the Radiant Knight | 6★ | 9 |
| Ling | 6★ | 9 |
| Mudrock | 6★ | 9 |
| Skadi the Corrupting Heart | 6★ | 9 |
| Archetto | 6★ | 9 |
| Irene | 6★ | 9 |
| Eyjafjalla the Hvít Aska | 6★ | 9 |
| Eunectes | 6★ | 9 |
| Carnelian | 6★ | 9 |
| Passenger | 6★ | 9 |
| Nightmare | 5★ | 9 |
| Broca | 5★ | 9 |
| Swire | 5★ | 9 |
| Skyfire | 5★ | 9 |
| Scene | 5★ | 9 |
| April | 5★ | 9 |
| Whisperain | 5★ | 9 |
| Tequila | 5★ | 9 |
| Texas | 5★ | 9 |
| Firewatch | 5★ | 9 |
| Franka | 5★ | 9 |
+135 more — see all in the Arknights Calculator.
To total several operators with a crafting-aware farm plan, use the Arknights Calculator.