Most swords and bladed weapons suffer from the problem of breakage, and it takes regular maintenance to keep it in a good condition, either sharpening it or outright reforging it. Not only it is time-consuming: no matter how regularly you repair them, your blades will inevitably break. So why bother keeping the same blade?
Enter the detachable blade, a type of bladed weapon which can detach its blade from its hilt and swap for a new one. As long as you have a hilt and spare blades, there's no need to sharpen your blades. Simply toss the old blade away and put on a new one, and here it is — a brand new sword!
Some weapons with detachable blades take one step further by launching the blade towards an enemy. As not many people would expect a sword to shoot its blade, it serves as a great tool for a surprise attack, a bayonet, or a weapon for killing someone afar stealthily.
Compare Bifurcated Weapon, a weapon built by attaching with multiple weapons, in which they are naturally detachable for another reason. See also Detachment Combat, Feather Flechettes and Spike Shooter.
For firearms counterpart, see Throw-Away Guns.
- The Vertical Maneuver Gear from Attack on Titan features a pair of dual blades, with their grips serving as the control of the hooks. Soldiers usually carry multiple blades in boxes built at the sides of their thighs, and the blades are swappable in case one of them gets stuck on a titan or broken.
- In Gamaran, Eima wields a naginata with a knife hidden in the base: in case of emergency he can pull out the knife and use it to attack at close range.
- Gundam Vidar's Burst Saber from Mobile Suit Gundam: Iron-Blooded Orphans can disconnect from its hilt and serve as an explosive should it gets stuck onto an enemy. The Vidar carries 6 spare blades in total and its pilot, Gaelio Bauduin, utilizes it in its full potential with his agile combat style.
- Miki Sayaka's cutlass from Puella Magi Madoka Magica, according to the production notes, has a trigger which can either turn it into a Whip Sword or launch and detonate the blade. While it is Dummied Out in the anime, it is used in a cutscene of the SLOT Puella Magi Madoka Magica slot machine, where she launches the blade towards a barrel in a Pop-Up Pirate-esque minigame to send Kyubey out of it. Unlike most examples, Sayaka simply summons her swords instead of swapping the blades.
- Slayers: Gourry disguises his legendary Sword of Light as a normal sword by keeping its Laser Blade turned off and socketing a common steel blade in its hilt. In a pinch, it can be removed by tapping a needle to a hidden spot on the hilt.
- Magical variation in Yaiba: during the final battle against Onimaru in the Orochi arc, Yaiba's Supreme King Sword breaks its blade... only to reveal a far more powerful blade made of pure energy. Not to be outdone, Onimaru does the same with his Demon King Sword, revealing a pitch black energy blade.
- Shuda from Rave Master gets serious against Deep Snow by removing the blade of his awesome katana like a second scabbard to reveal another blade made of solid fire underneath.
- RWBY: Second Generation: Orion's weapon works this way to make it more modular. It's how it can switch between its three modes.
- The Sword and the Sorcerer has the protagonist wielding a triple bladed sword - the two outer blades can be shot at enemies as seen here - 
- In The Punisher (2004) Franks pulls out a knife when ambushed by a hitman, when the hitman stops to mock him for bringing a knife a gun fight, Frank launches the blade into the hitman's neck.
- The Samuroids in The Flash (2014) can propel the blades of their katanas as projectile weapons.
- Ace Attorney Investigations: The embassies each have a collection of three knives with interchangeable blades. Since its a reoccurring theme that things traveled between the embassies, so does a knife.
- Assassin's Creed:
- In Assassin's Creed III Connor's Hidden Blades are capable of detaching in order to be used as knives.
- Assassin's Creed: Unity has the Phantom Blade - a combination of the franchise's signature Hidden Blade weapon with a crossbow, allowing its blade to be fired at enemies as a ranged attack.
- BlazBlue: in a Shout-Out to Attack on Titan, Hibiki's swords have detachable cutter-esque blades that he's shown replacing at the end of each match round. One of his Limit Breaks also start with him throwing the blades of his swords.
- Call of Duty: Black Ops has the Ballistic Knife, a spring-loaded knife that can be used for both melee or ranged attack by launching the blade, both of which are One-Hit Kill regardless the distance. It also swings faster than the standard melee attack with it equipped.
- Super Robot Wars: The SRX's Finishing Move, Tenjou Tenga Nendou Bakusai Ken (Heaven and Earth Psychoburst Sword) impales its opponent on a blade of volatile psychic energy, snaps it off at the hilt, and then detonates it as a bomb. Its upgraded form in Alpha 3, Banpreios, can generate these blades from its fists as part of its T-Link Blade Knuckle attack.
- Raven Branwen's weapon in RWBY. It's a long red sword with a bulky sheath which contains a rotating chamber of several dozen differently-colored spare blades. If the needs arise (such as when her blade is broken), she can sheathe the hilt before pulling out another blade and resuming combat. To add even more utility to the weapon, each color of blade she uses has a different property.
- The Ballistic Knife is a type of spring-loaded knife with detachable blade that can be launched to a far distance.
- Modelling knives can swap out its blade for a blade with a different shape or a spare blade should one becomes blunt.
- Cutters in general, should the blade becomes blunt, you can snap the blunt blade away and it's immediately sharpened. Some models can swap out an entire blade as well.
- Many skinning knives feature replacable blades, simply because it's far easier and quicker than restoring a dulled blade back to razor sharpness.