Buy RS3 Concentrated alloy bar
The concentrated alloy bar is a members only metal bar in RuneScape 3. It is a key part of making masterwork equipment, the top tier melee armour for smiths. Buying these bars saves you from smelting every type of bar yourself.
Making one bar the normal way takes level 99 Smithing. You need one bronze, iron, steel, mithril, adamant, rune, orikalkum, necronium, bane, and elder rune bar. You smelt them at any furnace using the metal bank. Each smelt takes 2.4 seconds and gives 10 Smithing experience.
Five concentrated alloy bars combine into one enriched alloy bar, which is the next step toward masterwork armour. You can also use one bar with a hammer at an anvil to upgrade 1000 armour spikes into 1000 alloy armour spikes. This needs level 99 Smithing and gives 100 experience.
These bars can also show up in metamorphic geodes, with up to ten found at once. The item is tradeable and noteable, and it weighs 1.814 kg. It cannot be alchemised or disassembled. If you want masterwork gear without the long grind of smelting bars, this item is what you need.