Materials now share an ItemID, seemed silly other wise.

core/features/DamagedItemDefinition.java

@@ -0,0 +1,64 @@
+package appeng.core.features;
+
+import net.minecraft.block.Block;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.tileentity.TileEntity;
+import appeng.api.util.AEItemDefinition;
+
+public class DamagedItemDefinition implements AEItemDefinition
+{
+
+	final Item baseItem;
+	final int damage;
+
+	public DamagedItemDefinition(ItemStack is) {
+		if ( is == null )
+		{
+			baseItem = null;
+			damage = -1;
+		}
+		else
+		{
+			baseItem = is.getItem();
+			damage = is.getItemDamage();
+		}
+	}
+
+	@Override
+	public Block block()
+	{
+		return null;
+	}
+
+	@Override
+	public Item item()
+	{
+		return baseItem;
+	}
+
+	@Override
+	public Class<? extends TileEntity> entity()
+	{
+		return null;
+	}
+
+	@Override
+	public ItemStack stack(int stackSize)
+	{
+		if ( baseItem == null )
+			return null;
+
+		return new ItemStack( baseItem, 1, damage );
+	}
+
+	@Override
+	public boolean sameAs(ItemStack comparableItem)
+	{
+		if ( comparableItem == null )
+			return false;
+
+		return comparableItem.getItem() == baseItem && comparableItem.getItemDamage() == damage;
+	}
+
+}