From the RuneScape Wiki, the wiki for all things RuneScape
Iron claws are a two handed melee weapon that are member's only.
Iron claws can be obtained by making them using the Smithing skill, trading with another player, or as a monster drop. The requirements for making them are completing the Death Plateau quest and 28 Smithing. To make them use an iron bar (with another in the inventory) on an anvil with a hammer in the inventory. This will grant the player 50 Smithing experience. For some odd reason, you wield 2 claws but you only use 1 in combat, in exception for the Dragon Claws and the Rune Claws special attack.