About weapons

Bronze
1
Apart from the comedy weapons, bronze weapons are the weakest weapons in all of RuneScape.
Iron
1
Iron weapons are stronger than bronze weapons.
Steel
5
Steel weapons are stronger than iron weapons.
Black
10
Black weapons are stronger than steel weapons.
Mithril
20
Mithril weapons are stronger than black weapons.
Adamant
30
Adamant weapons are stronger than mithril weapons.
Rune
40
Rune weapons are stronger than adamant weapons and are also the strongest weapons free players can wield, not counting Corrupt dragon (see below).
Granite
50
Granite weapons are limited to the Granite maul and Granite mace. Granite can only be wielded
Obsidian weapons are stronger than rune weapons. Obsidian can only be wielded by members.
Dragon
60
Dragon weapons are stronger than rune weapons. All offer a special attack, it is believed by some lower levels that all Dragon weapons special attacks offer a higher hit this is NOT true, to understand what their special attacks perform please refer to the item in question. Dragon can only be wielded by members.
Corrupt dragon
60
Corrupt Dragon weapons are stronger than rune weapons. They provide the same bonuses as normal Dragon equipment, and can be wielded by all players (but only members can use their special attacks). These weapons will disappear after 30 minutes of combat (on both PvP and non-PvP worlds). They are generally more expensive than normal dragon, so generally only free players decide to buy them.
Barrows
70
Barrows is the second strongest set of melee equipment in the game. Barrows can only be wielded by members. Each set of Barrows items (e.g. all of Verac the Defiled's armour plus his flail) give a special set effect that takes place as long as the full set is worn.
Ancient Warriors' Equipment
20/78
Ancient Warriors' Equipment is currently the strongest set of melee equipment in the game. The sets will disappear after one hour of combat, assuming the wearer has the level 78 requirements fulfilled. Otherwise, they will vanish after a mere fifteen minutes.
Godsword
75
The Godsword is considered by some to be the most powerful weapon in the entire game. It was released with the God Wars Dungeon.