Amount of quality depends on Item Level of item, with lower item level get more quality per stone. Quality increases the local damage of the weapon multiplicatively.
Every 1% quality improves the chance of getting more sockets or links by 1%.[1]
Many players also save Blacksmith's Whetstones for GavelsGavelOne Handed Mace Physical Damage: 54-101 Critical Strike Chance: 5.00% Attacks per Second: 1.15 Weapon Range: 1.1 metresRequires Level 60, 212 Str15% reduced Enemy Stun Threshold for the Cartographer's Chisel recipe.
Item acquisition
Blacksmith's Whetstone can drop anywhere.
Recipes
Blacksmith's Whetstone can be created from the following recipes:
The Master ArtisanThe Master Artisan520x Quality CurrencyPerfection is the standard, excellence will be handled on a case by case basis.
Random quality currency x20
A
1
The VoidThe Void1Reach into the Void and claim your prize.
Random divination card set exchange
A
Blacksmith's Whetstones can be obtained from slain enemies or purchased from some vendors. For example, Greust in the Forest Encampment and Hargan in The Sarn Encampment (Act 3) and (Act 8) will sell a Blacksmith's Whetstone in exchange for three Armourer's ScrapsArmourer's ScrapStack Size: 40Improves the quality of an armourRight click this item then left click an armour to apply it. Has greater effect on lower-rarity armours. The maximum quality is 20%.. Blacksmith's Whetstones may also be obtained from Artisan's Strongboxes.
One can sell any weapon with 20% quality to any vendor in exchange for a Blacksmith's Whetstone.
One can sell any number of weapons whose total quality is at least 40% to any vendor in exchange for a Blacksmith's Whetstone.
One can trade Hargan 8 Blacksmith's Whetstones in exchange for a Glassblower's BaubleGlassblower's BaubleStack Size: 20Improves the quality of a flaskRight click this item then left click a flask to apply it. Has greater effect on lower-rarity flasks. The maximum quality is 20%.. One can also sell a Blacksmith's Whetstone to any vendor for 4 Scrolls of WisdomScroll of WisdomStack Size: 40Identifies an itemRight click this item then left click an unidentified item to apply it..
Version history
Blacksmith's Whetstones were previously known as "Whetstone"s.
Item Quality has been reworked. The rarity of the item is no longer relevant when applying Cartographer's Chisels, Blacksmith's Whetstones, Armourer's Scraps, Glassblower's Baubles, and Catalysts to non-Unique items. Instead, the amount of Quality they provide is now based on the item level. These currencies now apply 20% Quality to very low-level equipment, with this amount reducing as the item level increases.
Quality bonuses on Armour, Weapons, and Flasks are now multiplicative. Weapons with full Quality will give 20% more Physical Damage, and Armour with full Quality will have 20% more local Defences.
Act 5 to 10 NPCs also sell Blacksmith's Whetstone. [Undocumented This change was not documented by any official sources. It was discovered through player testing or datamining.]
Tainted Blacksmith's WhetstoneTainted Blacksmith's WhetstoneStack Size: 20Randomises the quality of a corrupted weaponRight click this item then left click a corrupted weapon to apply it. The maximum random quality is 20%.
The Sharpened BladeThe Sharpened BladeThe metal softens beneath the stone, reshaping with great ease.You will greatly enhance the quality of a weapon with a single Blacksmith's Whetstone.Right-click to add this prophecy to your character.
GavelsGavelOne Handed Mace
for the Cartographer's Chisel recipe.
Emperor's Luck
Emperor's Luck
55x CurrencyThe house always wins.
The Master Artisan
520x Quality CurrencyPerfection is the standard, excellence will be handled on a case by case basis.
The Void
1Reach into the Void and claim your prize.
Armourer's ScrapsArmourer's ScrapStack Size: 40Improves the quality of an armourRight click this item then left click an armour to apply it. Has greater effect on lower-rarity armours. The maximum quality is 20%.
. Blacksmith's Whetstones may also be obtained from Artisan's Strongboxes.
Glassblower's BaubleGlassblower's BaubleStack Size: 20Improves the quality of a flaskRight click this item then left click a flask to apply it. Has greater effect on lower-rarity flasks. The maximum quality is 20%.
. One can also sell a Blacksmith's Whetstone to any vendor for 4 
Scrolls of WisdomScroll of WisdomStack Size: 40Identifies an itemRight click this item then left click an unidentified item to apply it.
.
Tainted Blacksmith's WhetstoneTainted Blacksmith's WhetstoneStack Size: 20Randomises the quality of a corrupted weaponRight click this item then left click a corrupted weapon to apply it. The maximum random quality is 20%.
The Sharpened BladeThe Sharpened BladeThe metal softens beneath the stone, reshaping with great ease.You will greatly enhance the quality of a weapon with a single Blacksmith's Whetstone.Right-click to add this prophecy to your character.