diff --git a/src/entity/item/tool.rs b/src/entity/item/tool.rs
index 4d5dc59..a5a6645 100644
--- a/src/entity/item/tool.rs
+++ b/src/entity/item/tool.rs
@@ -218,6 +218,39 @@ impl ToolType {
         }
     }
 
+    pub fn max_stack(&self) -> u8 {
+        match self {
+            ToolType::Monomate => 10,
+            ToolType::Dimate => 10,
+            ToolType::Trimate => 10,
+            ToolType::Monofluid => 10,
+            ToolType::Difluid => 10,
+            ToolType::Trifluid => 10,
+            ToolType::SolAtomizer => 10,
+            ToolType::MoonAtomizer => 10,
+            ToolType::StarAtomizer => 10,
+            ToolType::Antidote => 10,
+            ToolType::Antiparalysis => 10,
+            ToolType::Telepipe => 10,
+            ToolType::TrapVision => 10,
+            ToolType::Monogrinder => 99,
+            ToolType::Digrinder => 99,
+            ToolType::Trigrinder => 99,
+            ToolType::PowerMaterial => 99,
+            ToolType::MindMaterial => 99,
+            ToolType::EvadeMaterial => 99,
+            ToolType::HpMaterial => 99,
+            ToolType::TpMaterial => 99,
+            ToolType::DefMaterial => 99,
+            ToolType::LuckMaterial => 99,
+            ToolType::Addslot => 99,
+            ToolType::PhotonDrop => 99,
+            ToolType::PhotonSphere => 99,
+            ToolType::PhotonCrystal => 99,
+            _ => 1,
+        }
+    }
+
     pub fn value(&self) -> [u8; 3] {
         match self {
             ToolType::Monomate => [0x03, 0x00, 0x00],