Abstract: An axially compact brake is disclosed according to the teachings of the present invention as being spring engaged and fluid released for rotationally controlling an electric motor shaft for driving a machine, robot, or other apparatus component. The brake includes a housing formed by an air-chamber housing portion and an annular plate. The air-chamber housing portion includes a friction interface disc and an axial cylindrical member for reciprocally receiving an annular piston to form a fluid pressure cylinder. The annular plate is secured to the cylindrical member and includes torque pins extending into the piston. Coil springs extend axially between the annular plate and the piston. The housing portion has a square outer perimeter defining mounting pads at its corners for sandwiching the housing between the apparatus component and the motor.