over 3 years ago - Shurenai - Direct link
I think it's a case of 'the description hasn't been copied across from the recipe to the item itself', As iirc the timed explosive recipe states that it only functions on doors and safes, which is the purpose of those timed explosives- safe cracking, door busting, not wall breaking.

The block damage listed works against doors and safes, but against normal blocks it does significantly less; this way you can crack a door or safe without, yknow, exploding the entire room, or blowing out the floor underneath ruining the loot/entryway.