The infernal axe is a special axe that requires level 61 Woodcutting to use. It is created by using a smouldering stone on a dragon axe, requiring level 61 Woodcutting and level 85 Firemaking to create, which cannot be boosted. Assembling an infernal axe will grant you 350 Firemaking xp and 200 Woodcutting xp. Chopping trees with the infernal axe will grant a 1/3 chance the logs will be burnt as they are chopped. This will give 50% of the Firemaking experience that would usually be gained by using a tinderbox to burn the logs. Redwood logs can be burnt this way even without having the required Firemaking level to light them.
The infernal axe will be able to burn 5,000 logs before degrading, requiring another smouldering stone or dragon axe to recharge it. When fully depleted, you can still use it as a regular dragon axe.
The infernal axe possesses the same special attack as the dragon axe, in which it boosts a players Woodcutting level by 3 and requires 100% special to use.
When fighting the Wintertodt, the infernal axe does not consume bruma roots, acting instead as a regular axe. The same can be said for chopping sulliuscep mushrooms.