Drill Spikes are a type of ammunition compatible with some Spike Throwers. It deals high Impact and Tear damage on impact, as well as damage and tear over time as the spike drills into its target. It is the only type of ammunition capable of Tear damage for Spike Throwers.
If a Drill Spike hits a machine's legs (or anywhere on the body of Stormbirds, and on the lower body of Slitherfangs), it's extremely high Knockdown Power from both the initial hit and the damage over time will quickly cause the Knockdown status, incapacitating the machine for several seconds.