Adamant arrowheads are items that can be made at 75 Smithing, granting 62.5 experience per Adamant bar. They can be fletched into adamant arrows at level 60 Fletching when used with headless arrows, which are made by using arrow shafts with feathers, granting 150 experience per 15 arrows made. They were commonly bought because they used to be the only arrowheads that earned money, however, since the 1 February Free Trade Update, adamant arrows are worth roughly 30 coins less than the arrowheads.
Adamant arrowheads can be bought at Hickton's Shop, in Catherby.
At current Grand Exchange prices, producing 15 Arrowheads will gain the player -1,449 coins profit (-23.18 coins per XP), without a Sacred clay hammer.