Grindstone

Grindstones are crafting stations found in The Elder Scrolls V: Skyrim.

Overview
Grindstones can be used to improve weapons, by sharpening them and adding weight for extra damage.

Weapons no longer have durability, unlike previous games, making the increase in damage and enchantments the only way to upgrade a weapon. Grindstones may be found in almost every corner of Skyrim's cities, towns, and even in mines and caves.

Using a Grindstone increases your Smithing level, although to a lesser degree than actually forging a weapon. Appropriate metal ingots are required to upgrade each item (i.e., ebony ingot for ebony sword). There are six levels of upgrade available (from least to greatest): fine, superior, exquisite, flawless, epic, and legendary. Each upgrade level has a required skill level, and this level can be reduced with the perk associated with the type of weapon that the player wishes to upgrade.

Notable information

 * Occasionally, when upgrading two of the same weapons, the weapons will no longer stack in the inventory/favorites list when one or both are equipped. This problem will fix itself only when both weapons aren't being used.
 * Grindstones can be found in nearly every smithing store.
 * Refined weapons cannot be bought (a flawless weapon) unless it is sold to them first.
 * Outside of Lost Valley Redoubt a dead Nord can be found with his head resting on a grindstone and blood everywhere. It's possible that the Forsworn nearby might have exploited the grindstone as a torture tool or a method of execution.

Bugs

 * If you kill an NPC who is using the Grindstone, it will continue working.
 * Being very near or operating a Grindstone will sometimes cause all in-game audio thereafter to be accompanied by annoying crackling. Quitting the game and restarting should fix this.
 * If you stand still, Serana will start to use a grindstone if one is nearby, and she leaves it suddenly to fight an enemy, it will continue working indefinitely, sound effects and all.