Farmer's Delight knives always deal 2.5 hearts less damage than swords made of the same material. Twilight Delight's ironwood, steeleaf and knightmetal knives do not respect this rule, and have incorrect attack values.
Ironwood sword deals 6 damage, so the ironwood knife should deal 3.5 damage. It instead deals 5.5.
Steeleaf sword deals 7 damage, so the ironwood knife should deal 4.5 damage. It instead deals 5.5.
Ironwood sword deals 7 damage, so the ironwood knife should deal 4.5 damage. It instead deals 5.5.