Iron knives can be made using the Smithing skill at level 22. One iron barcreates 5 iron knives and grants 25 smithing experience. Buying iron bars and smithing them into knives is usually profitable depending on prices at the time. Like all knives they have an incredibly fast fire rate the same as darts. Along withbronze knives which are the same range bonus as iron darts, are considered to be one of the fastest and most efficient ways to gain Ranged experience.