A knife according to the present disclosure includes a housing and a blade. The blade includes a blade edge adapted to engage a material, and the blade is coupled to a blade shuttle. The blade and blade shuttle are substantially enclosed within the housing when the blade shuttle is in a retracted position, and the blade is extended from the housing when the blade shuttle is in an extended position. The blade shuttle is adapted to be conveyed to the retracted position based on the blade receiving a force directed substantially perpendicular to the blade edge.