The World Eaters of Warhammer 40,000 use awesome looking axes with spinning chainsaws on the head. Fueled by pure, undiluted testosterone, these warriors of Khorn ride the battlefield on war bikes blasting explosive rounds and cracking skulls open with their chain axes as the spinning teeth spray gore.
But aside from spraying gore, those chain axes don’t do much that a regular ax couldn’t do better.
The other chain weapon in Warhammer 40,000, the chainsword, has also been accused of impracticality. Going by the standard design seen in models, this is fair, but it could actually work with a few modifications. But the idea of a chain ax is flawed at the very basic level because most of the damage from the impact of the chain ax would come from the force of the impact its self.
Historically, cavalry riders and even pirates often didn’t even bother to sharpen their swords. The weight of the blade and the force of the blow, especially in the case of a cavalry rider charging the enemy on horseback, served well enough to crack bones and take an enemy out of the fight, or leave them open for a stab from the point of these blades. (The tip typically was sharp, even if the edge was not.)
The unsharpened blades did have a weakness. If the swordsman were ever required to slice a part of an enemy’s body, situations that might happen in very close combat, the swordsman would not be able to do it. A glancing blow with a sharpened edge might also do much more damage to an enemy than an unsharpened blade.
A weapon like a chainsword would probably be used more like chainsaws than swords. Although these hard blows would be necessary in combat situations, the wielder of a chainsword would also need be slow with his or her movements, both because of the weight of the engines and to make use of the spinning teeth. The advantage of a chainsword is that it could mangle a part of an enemy’s body simply by coming into contact with it, without requiring force behind the blow, and the teeth could also assist in a downward slash to shred the enemy’s flesh.
The chain ax could be used in a similar way, with both cons and pros. The spinning teeth on a chain ax have less of an area to work with, but because the face of the ax juts out from the shaft, the warrior could press against the back of the ax for added force. Chainsword designs usually have a guard behind the blade for a similar purpose, but in the case of a chainsword, because the distance between the guard and the chain, this guard would get caught on the enemy’s armor or body.
The chain ax might even have advantages over the sword. In some designs, the chain ax could be used to hook a person at the arm or leg, sawing into them even as the weapon grabs hold.
For the contemporary use of axes in battle, hacking people apart, the spinning of the teeth would contribute very little because of the speed and force of the blow. The blow would come to fast to really shred the flesh and the damage the spinning teeth did cause would only be redundant to the damage inflicted by the force of the blow. A solid edge might even be preferable to the chainsaw teeth because a solid blade would more easily crush or cleave a skull with the even distribution of the force of the impact.
Aside from that, the chain and teeth would be more easily damaged than a solid metal ax. Chainsaws, in work environments, frequently jam with wood debris and the teeth dull easily with heavy use.
But again, the chain ax would have its uses, even if the teeth didn’t aid much during those satisfying skull crunches. And the guys who ritualistically chain their weapons to their arms aren’t looking for strict practicality to begin with. It’s all about blood for the Blood God, skulls for the Skull Throne, and baddass for badass’ sake.