Tank Mines are a utility item, available only to Engineer. Depending on Mine Carrier and Tank Mine ranks, an Engineer can carry and deploy up to 5 Tank Mines at the same time. 

Cost: 50 Nanites
Approximate damage: 1250 @ 2m – 100 @ 5m (?)
Damage Resist Type: 9 – Tank Mine

(?) – Maximum damage is correct, but other numbers can potentially vary a bit. Since Tank Mine damage is hidden in game and the API, we have to rely on in-game testing to determine damage, and fractions of meters are hard to test for. 

Tank Mines have their own unique Damage Resist Type, and most vehicles take a large amount of bonus damage from Tank Mines. You can use the Toolbox to calculate Tank Mine damage to various vehicles.

All ground vehicles have access to Mine Guard defensive certification, which significantly reduces damage from Tank Mines.

Tank Mines have a small trigger radius of about 1m. A vehicle has to basically ride over the mine in order to trigger it. 

Tank Mines have a 4 second arming time, and will not automatically detonate until it is over, but they can be detonated by outside sources during that time, including splash damage from other explosives.

Tank Mines ignore infantry, but they will trigger on MAXes. One Tank Mine will kill a stock MAX, but MAXes with Ordance Armor will require two.