An ort rune is a low tier rune that can be socketed into armor and weapons. You can cube 3 ral runes together to get an ort rune. You can also obtain an ort rune from nightmare countess. You can get an ort rune from the normal hellforge quest.
An ort rune requires level 21 to use.
Horadric cube recipes with ort runes
transmute 3 ort runes to create a thul rune
transmute normal rare weapon, a ort rune, a amn rune, and a perfect sapphire to create an exceptional rare weapon of the same type
transmute any non-ethereal weapon and a ort rune to fully repair the weapon
transmute any non-ethereal weapon, a ort rune, and any chipped gem to fully repair and recharge the weapon