Handamage is one person's term for when you over power some hand work you're doing, and slip and cut your hand or some incredibly frustrating thing like that.

Example: Loosening a corroded nut off of a bolt with a slightly improperly sized wrench. You're really cranking on the little fucker, and then your wrench slips off the nut and all your knuckles' skin (after having a brief rendezvous with something inevitably close by and made of metal) decides to take a 1-month vacation. The nut remains on the bolt, with a smugness that no one before or since had realized could come from an inanimate object.