Basic weapons can be crafted using resources available on the island but the strongest weapons can only be obtained as drops from Zombies or found in chests. Chests are found in or near buildings, or by digging at the X’s as shown in the map. There are ranged and melee weapon types.
thus, How do you get iron in Radiation Island?
Iron is found when mining rocks or Iron Ore veins. String is a crafted item made from fiber which is gathered from bushes and plants when exploited with machetes or a free hand. A Iron Axe is also used as a Iron Pick-Axe as it can mine ores.