Grindstone

**Grindstone** is one of the Attachments that can be bought from the Weaponsmith or obtained from the Redeem Machine with the relevant voucher.

## Effects

Each Grindstone's name may have **White/Blue/Purple** color, indicating that it increases a weapon's damage by **1/2/3/4** once attached.

* A Grindstone of +1 damage can only appear for weapons in Group B below.

If the weapon has any secondary attack (like the ball of Baseball Bat), it is also affected.

## Compatible Weapons

Grindstone can be compatible with two groups of weapons:

* Group A:
	+ Weapons classified as Melee Weapons in the Forge Table (except Laser Swords and Lasso Gun).
	+ Bows and Crossbows (except Shuddering Thunder).
		- Bows have a special effect on Grindstones: if fully charged, the attachment will add x2 of its base damage. For example, a Purple Grindstone, if fired with a fully charged Crystal Bow, will deal a total of 24 (48 critical) damage = 16 from the bow + (4x2) from the attachment. Another example is a White Grindstone fired with a fully charged Slingshot, dealing a total of 9 (18 critical) damage = 5 from the slingshot + (2x2) from the attachment.
	+ Throwing weapons with melee attack: Crispy Bone, Jack and Mary, Javelin, Throwing Axe, Bamboo, Frost Spear, Heavy Hunter Axe, Giant Axe.
	+ Some Miscellaneous weapons: Crowbar, Iron Claw, Umbrella, Vine, Green Basin, Badminton Racket, Baseball Bat.
		- For Green Onions, Meat, Heavenly Sword and Carrot, both original form and variations (like Centennial Carrot) are included as well (except for the Grilled Heavenly Sword).
* Group B:
	+ Normal Throwing weapons: Ninja Stars, Paper Slip, Damaged Blade, Wrenches, Spike Knives, Boomerang, Ice Spikes, Ninja Stars Plus, Electric Ninja Stars, Green Essence, Molotov Cocktail, Hand Grenade, Windforce Ninja Stars.
	+ Buckler.

### Rarity Limit

Certain weapons can only equip a Grindstone of a given rarity or worse, but not better.

* Limit: White
	+ Hero Bow, Magic Bow

## Notes

* Red/Legendary and Magenta/Mythical weapons cannot have Grindstone, or any other attachments.
* A Grindstone from one weapon can only be compatible with other weapons if they are in the same group.

## Trivia

* Before Update 2.5.0, the Grindstone could only affect certain secondary attacks, like the explosion damage of Explosive Crossbow and blast damage of Star Bow.
* At some point, the Nunchaku could only equip a Grindstone of Blue rarity or lower. This has been changed in an unknown update, possibly Update 2.7.0.
* Before Update 2.8.0, when the Thunder Sword was still an Orange/Epic weapon, it could use a Grindstone, but it couldn't be any rarity higher than White.
	+ This became a disaster since the change in 2.5.0, as the damage boost was added to every attack it can perform.
* After an unkown update, the way Grindstones work with Bows was changed. Making the Grindstones add x2 their damage if the bow is fully charged, as opposed to simply their listed damage, which is what happens to all other weapons.
	+ This stacks with the  or  conditions: a Purple Grindstone typically has 4 damage, the "Weapon attack +100%, fire rate -50%" will double it to 8, and when the bow is fully charged, this bonus value is further increased to 16.
* Before Update 3.4.2, Vorpan cannot equip grindstone, despite being a melee weapon.