The Giga Drill Break (often incorrectly called Giga Drill Breaker) is a technique originally used by Kamina, and has since become the signature attack of Simon, along with Lagann Impact. It involves concentrating a large amount of Spiral Power into a disproportionately large drill (usually referred to as a "Giga Drill") and performing a powerful charge at a target.
Gurren Lagann first performs a Giga Drill Break when Simon and Kamina use it to defeat Thymilph during the siege of Dai-Gunzan. It isn't until Simon uses it against Guame's custom Gunmen, the Gember, that it becomes his signature move, and is used against most of the series' stronger enemies.
The move, however, fails to defeat Lordgenome, as his Lazengann is able to bite down on the Giga Drill when it is about to pierce the torso of the mech, and break it with its teeth. This is one of the first cases in which a Giga Drill is able to break, the recurring factor being that those opponents are very experienced with Spiral Power.
Later on, Simon develops a derivative of the technique called the Giga Drill Maximum. Instead of charging forward with a single massive drill, Gurren Lagann manifests dozens of smaller (but still proportionately large) Giga Drills all over its body, forming a powerful defense that can absorb or reflect enemy attacks in a massive explosion.
In the case of Super Galaxy Gurren Lagann, the drills used in the technique are actually the large drills on its shoulders, which can connect on either hand or on top of each other depending on the situation.
The Super Tengen Toppa Gurren Lagann uses it, and to date, is along with the Super Granzeboma, one of the two largest seen Spiral produced entities. The Super Tengen Toppa Giga Drill is the fourth most lethal entity, behind both the Anti-Spiral's and Gurren Lagann's last seen Giga Drills, and Simon's final Giga Drill. Since the Super Tengen Toppa is 52.8 billion light years tall according to the official guide book from GAINAX (仕事魂), and the Super Tengen Toppa Giga Drill is over 180 times larger in cone area, it has a multiversal scale the size of over 100 universes; the Anti-Spiral dimension they were fighting in has an omniversal scale equivalent to thousands of universes, which was destroyed in the clash between the Super Tengen Toppa Giga Drill and the Anti-Spiral Giga Drill.
One of the only mechas besides Gurren-Lagann seen performing a Giga Drill Break. Kittan Bachika has his Gunmen perform this move as a last resort in destroying the Death Spiral Machine in order to save Team Dai-Gurren from the Galactic Spiral Abyss. What is notable about this version is that the Giga Drill used is much larger in proportion to the body of the mech than is normal, comparable to the proportions of the Giga Drill used by Super Tengen Toppa Gurren Lagann in the second movie adaption of the series. Also, the drill used was initially a broken Giga Drill that Kittan "borrowed" as a good-luck charm, but it transformed into a fully-functional Giga Drill when Kittan initiated the technique.
Super Granzeboma uses its own move, the aptly-named Anti-Spiral Giga Drill Break, in order to counter Team Dai-Gurren's Super Tengen Toppa Giga Drill Break. When the two collide, they cause distortions in the dimension they are fighting in, pulling in everything and causing the space to become dark. Super Granzeboma eventually breaks through, but its Giga Drill is broken when faced by all of the other forms of Gurren Lagann in succession, eventually giving way to the original mech's drill.
- All forms of Gurren Lagann have used at least one Giga Drill Break except its titular form, the Tengen Toppa Gurren Lagann. The mech did, however, still use Giga Drills.
- In the orginal Japanese anime, the voice actors said "Giga Drill Break", but because of the style in which they spoke, were misinterpreted as "Giga Drill Breaker". This was followed by subtitles that labeled it as such.
- One of Lazengann's ultimate attacks engulfs its lower body with all of its drill-tentacles to form a single massive drill similar to a Giga Drill. However, this does not appear to be a true Giga Drill Break, but merely a technique very similar to it.