Switch Axes are forged with Phials built into them. The type of Phial the axe has depends on what type of Switch Axe you are using. Phials have a great effect on the weapon itself, however, Phials can only be used in Sword Mode. In Monster Hunter Tri, there are four types of Phials. These include the elemental, power, dragon, and para phials.
Elemental Phial: These Phials increase the amount of elemental damage the weapon deals.
Power Phial: These Phials increase the amount of raw damage the weapon deals.
Dragon Phial: Adds the element of Dragon to the weapon.
Para Phial: Adds the paralysis attack attribute to the weapon.
| Elemental Phial | Jhen Mohran Series | Bolt Axe Series | Alatreon Series | Barioth Series | |
| Power Phial | Bone Axe Series | High Bolt Axe Series | Agnaktor Series | Ceadeus Series | Sinister Saints/ Pirate Series |
| Dragon Phial | Crystal Series | ||||
| Para Phial | Barroth Series |